diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 6f727f4..68d67ad 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -13,6 +13,25 @@ env:
   CARGO_TERM_COLOR: always
 
 jobs:
+  python-quality:
+    name: Ruff and Pyright
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - uses: actions/setup-python@v6
+        with:
+          python-version: "3.10"
+      - name: Install Python quality tools
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install --group dev
+      - name: Lint Python
+        run: ruff check python
+      - name: Check Python formatting
+        run: ruff format --check python
+      - name: Check Python types
+        run: pyright
+
   test:
     runs-on: ubuntu-latest
 
@@ -63,3 +82,9 @@ jobs:
 
       - name: Run Python tests
         run: python -m pytest python/tests
+
+      - name: Run Python examples
+        run: |
+          for example in python/examples/*.py; do
+            python "$example" > /dev/null
+          done
diff --git a/pyproject.toml b/pyproject.toml
index 2dbeaa4..68fbad0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -34,3 +34,21 @@ Documentation = "https://github.com/RustedBytes/fasttime/blob/main/python/README
 features = ["pyo3/extension-module", "python", "std"]
 python-source = "python"
 module-name = "fasttime"
+
+[dependency-groups]
+dev = ["pytest>=8", "ruff==0.16.10", "pyright==1.1.414"]
+
+[tool.ruff]
+target-version = "py310"
+line-length = 88
+
+[tool.ruff.lint]
+select = ["E4", "E7", "E9", "F", "I", "UP", "B"]
+
+[tool.pyright]
+include = ["python"]
+extraPaths = ["python"]
+pythonVersion = "3.10"
+typeCheckingMode = "standard"
+# The implementation is a Rust extension; its API is declared in fasttime.pyi.
+reportMissingModuleSource = "none"
diff --git a/python/benchmarks/string_formatting.py b/python/benchmarks/string_formatting.py
new file mode 100644
index 0000000..85fdfda
--- /dev/null
+++ b/python/benchmarks/string_formatting.py
@@ -0,0 +1,41 @@
+"""Compare installed release wheels in separate virtual environments.
+
+Run with each environment's Python. Results are median nanoseconds per call,
+including Python dispatch, over seven repetitions of 200,000 calls.
+"""
+
+import json
+import statistics
+import timeit
+from collections.abc import Callable
+
+import fasttime
+
+values = {
+    "date": fasttime.Date(2024, 6, 15),
+    "time": fasttime.Time(12, 30, 45, nanosecond=123456789),
+    "datetime": fasttime.DateTime.parse("2024-06-15T12:30:45.123456789Z"),
+    "offset": fasttime.OffsetDateTime.parse("2024-06-15T12:30:45.123456789+05:30"),
+    "duration": fasttime.Duration.nanoseconds(123456789),
+    "weekday": fasttime.Weekday.MONDAY,
+}
+
+
+def measure(op: Callable[[object], str], value: object) -> float:
+    return round(
+        statistics.median(timeit.repeat(lambda: op(value), number=200000, repeat=7))
+        * 1e9
+        / 200000,
+        1,
+    )
+
+
+print(
+    json.dumps(
+        {
+            f"{name}/{op.__name__}": measure(op, value)
+            for name, value in values.items()
+            for op in [str, repr]
+        }
+    )
+)
diff --git a/python/examples/basic_usage.py b/python/examples/basic_usage.py
index b7a2242..debdfe4 100644
--- a/python/examples/basic_usage.py
+++ b/python/examples/basic_usage.py
@@ -19,7 +19,7 @@ def main():
     print(f"Year: {date.year}, Month: {date.month}, Day: {date.day}")
     print(f"Weekday: {date.weekday()}")
     print(f"Day of year: {date.ordinal()}")
-    
+
     # Add/subtract days
     tomorrow = date.add_days(1)
     yesterday = date.add_days(-1)
@@ -45,7 +45,7 @@ def main():
     print(f"DateTime: {dt}")
     print(f"Date component: {dt.date}")
     print(f"Time component: {dt.time}")
-    
+
     # Get current time
     now = fasttime.DateTime.now_utc()
     print(f"Current UTC time: {now}")
@@ -54,25 +54,25 @@ def main():
     # 4. Working with Durations
     print("4. Working with Durations")
     print("-" * 40)
-    
+
     # Create durations
     one_hour = fasttime.Duration.seconds(3600)
     one_day = fasttime.Duration.seconds(86400)
     half_second = fasttime.Duration.milliseconds(500)
-    
+
     print(f"One hour: {one_hour.total_seconds()} seconds")
     print(f"One day: {one_day.total_seconds()} seconds")
     print(f"Half second: {half_second.total_seconds()} seconds")
-    
+
     # Add durations
     total = one_hour + half_second
     print(f"One hour + 500ms: {total.total_seconds()} seconds")
-    
+
     # Add duration to datetime
     later = dt.add_duration(one_hour)
     print(f"Original: {dt}")
     print(f"One hour later: {later}")
-    
+
     # Calculate difference
     diff = later.difference(dt)
     print(f"Difference: {diff.total_seconds()} seconds")
@@ -83,7 +83,7 @@ def main():
     print("-" * 40)
     date1 = fasttime.Date(2024, 1, 1)
     date2 = fasttime.Date(2024, 12, 31)
-    
+
     print(f"{date1} < {date2}: {date1 < date2}")
     print(f"{date1} == {date2}: {date1 == date2}")
     print(f"{date1} > {date2}: {date1 > date2}")
@@ -108,10 +108,10 @@ def main():
     print("-" * 40)
     epoch = fasttime.Date.from_days_since_unix_epoch(0)
     print(f"Unix epoch (day 0): {epoch}")
-    
+
     days = date.days_since_unix_epoch()
     print(f"{date} is {days} days since epoch")
-    
+
     reconstructed = fasttime.Date.from_days_since_unix_epoch(days)
     print(f"Reconstructed: {reconstructed}")
     print(f"Match: {date == reconstructed}")
diff --git a/python/examples/durations.py b/python/examples/durations.py
index a68a678..c9e4f23 100644
--- a/python/examples/durations.py
+++ b/python/examples/durations.py
@@ -14,12 +14,12 @@ def main():
     # 1. Creating Durations
     print("1. Creating Durations")
     print("-" * 40)
-    
+
     seconds = fasttime.Duration.seconds(60)
     millis = fasttime.Duration.milliseconds(500)
     micros = fasttime.Duration.microseconds(1000)
     nanos = fasttime.Duration.nanoseconds(123_456_789)
-    
+
     print(f"60 seconds: {seconds.total_seconds()} s")
     print(f"500 milliseconds: {millis.total_seconds()} s")
     print(f"1000 microseconds: {micros.total_seconds()} s")
@@ -29,14 +29,14 @@ def main():
     # 2. Duration Arithmetic
     print("2. Duration Arithmetic")
     print("-" * 40)
-    
+
     one_hour = fasttime.Duration.seconds(3600)
     thirty_minutes = fasttime.Duration.seconds(1800)
-    
+
     total = one_hour + thirty_minutes
     difference = one_hour - thirty_minutes
     negated = -thirty_minutes
-    
+
     print(f"1 hour + 30 minutes: {total.total_seconds()} seconds")
     print(f"1 hour - 30 minutes: {difference.total_seconds()} seconds")
     print(f"-(30 minutes): {negated.total_seconds()} seconds")
@@ -45,15 +45,15 @@ def main():
     # 3. Adding Durations to DateTimes
     print("3. Adding Durations to DateTimes")
     print("-" * 40)
-    
+
     start = fasttime.DateTime.parse("2024-01-01T00:00:00Z")
     print(f"Start: {start}")
-    
+
     # Add various durations
     one_day = fasttime.Duration.seconds(86400)
     one_week = fasttime.Duration.seconds(86400 * 7)
     one_year = fasttime.Duration.seconds(86400 * 365)
-    
+
     print(f"+1 day:  {start.add_duration(one_day)}")
     print(f"+1 week: {start.add_duration(one_week)}")
     print(f"+1 year: {start.add_duration(one_year)}")
@@ -62,10 +62,10 @@ def main():
     # 4. Calculating Time Differences
     print("4. Calculating Time Differences")
     print("-" * 40)
-    
+
     dt1 = fasttime.DateTime.parse("2024-01-01T12:00:00Z")
     dt2 = fasttime.DateTime.parse("2024-01-01T18:30:45Z")
-    
+
     diff = dt2.difference(dt1)
     print(f"Time 1: {dt1}")
     print(f"Time 2: {dt2}")
@@ -76,10 +76,10 @@ def main():
     # 5. Measuring Intervals
     print("5. Measuring Intervals")
     print("-" * 40)
-    
+
     meeting_start = fasttime.DateTime.parse("2024-06-15T09:00:00Z")
     meeting_end = fasttime.DateTime.parse("2024-06-15T10:30:00Z")
-    
+
     duration = meeting_end.difference(meeting_start)
     print(f"Meeting start: {meeting_start}")
     print(f"Meeting end:   {meeting_end}")
@@ -89,10 +89,10 @@ def main():
     # 6. Comparing Durations
     print("6. Comparing Durations")
     print("-" * 40)
-    
+
     short = fasttime.Duration.seconds(10)
     long = fasttime.Duration.seconds(100)
-    
+
     print(f"Short duration: {short.total_seconds()} s")
     print(f"Long duration:  {long.total_seconds()} s")
     print(f"short < long:   {short < long}")
@@ -103,11 +103,11 @@ def main():
     # 7. Working with Nanoseconds
     print("7. Working with Nanosecond Precision")
     print("-" * 40)
-    
+
     # High-precision timestamps
     dt_start = fasttime.DateTime.parse("2024-01-01T00:00:00.000000000Z")
     dt_end = fasttime.DateTime.parse("2024-01-01T00:00:00.123456789Z")
-    
+
     nano_diff = dt_end.difference(dt_start)
     print(f"Start:      {dt_start}")
     print(f"End:        {dt_end}")
@@ -118,15 +118,15 @@ def main():
     # 8. Negative Durations
     print("8. Negative Durations")
     print("-" * 40)
-    
+
     future = fasttime.DateTime.parse("2024-12-31T23:59:59Z")
     past = fasttime.DateTime.parse("2024-01-01T00:00:00Z")
-    
+
     # Future - past = positive
     forward = future.difference(past)
     # Past - future = negative
     backward = past.difference(future)
-    
+
     print(f"Future: {future}")
     print(f"Past:   {past}")
     print(f"Future - Past: {forward.total_seconds()} seconds (positive)")
@@ -136,7 +136,7 @@ def main():
     # 9. Common Duration Constants
     print("9. Common Duration Values")
     print("-" * 40)
-    
+
     constants = [
         ("1 millisecond", fasttime.Duration.milliseconds(1)),
         ("1 second", fasttime.Duration.seconds(1)),
@@ -145,7 +145,7 @@ def main():
         ("1 day", fasttime.Duration.seconds(86400)),
         ("1 week", fasttime.Duration.seconds(86400 * 7)),
     ]
-    
+
     for name, dur in constants:
         print(f"{name:15} = {dur.total_nanos():>20} nanoseconds")
     print()
diff --git a/python/examples/parsing.py b/python/examples/parsing.py
index c558567..d5a98cd 100644
--- a/python/examples/parsing.py
+++ b/python/examples/parsing.py
@@ -14,14 +14,14 @@ def main():
     # 1. Parsing Dates
     print("1. Parsing Dates (YYYY-MM-DD)")
     print("-" * 40)
-    
+
     date_strings = [
         "2024-01-01",
         "2024-12-31",
         "2000-02-29",  # Leap year
         "1970-01-01",  # Unix epoch
     ]
-    
+
     for s in date_strings:
         date = fasttime.Date.parse(s)
         print(f"{s:12} -> {date} (weekday: {date.weekday()})")
@@ -30,7 +30,7 @@ def main():
     # 2. Parsing Times
     print("2. Parsing Times (HH:MM:SS[.fffffffff])")
     print("-" * 40)
-    
+
     time_strings = [
         "00:00:00",
         "12:00:00",
@@ -40,7 +40,7 @@ def main():
         "14:30:45.123456",
         "14:30:45.123456789",
     ]
-    
+
     for s in time_strings:
         time = fasttime.Time.parse(s)
         print(f"{s:25} -> {time}")
@@ -49,7 +49,7 @@ def main():
     # 3. Parsing UTC DateTimes
     print("3. Parsing UTC DateTimes (ISO 8601 / RFC 3339)")
     print("-" * 40)
-    
+
     datetime_strings = [
         "2024-01-01T00:00:00Z",
         "2024-12-31T23:59:59Z",
@@ -57,7 +57,7 @@ def main():
         "2024-06-15T12:30:45.5Z",
         "2024-06-15T12:30:45.123456789Z",
     ]
-    
+
     for s in datetime_strings:
         dt = fasttime.DateTime.parse(s)
         print(f"{s:40} -> {dt}")
@@ -67,7 +67,7 @@ def main():
     # 4. Parsing OffsetDateTimes (with timezone offsets)
     print("4. Parsing OffsetDateTimes (RFC 3339 with offsets)")
     print("-" * 40)
-    
+
     offset_datetime_strings = [
         "2024-06-15T12:30:45Z",
         "2024-06-15T12:30:45+00:00",
@@ -75,7 +75,7 @@ def main():
         "2024-06-15T12:30:45-08:00",
         "2024-06-15T12:30:45.123456789+02:00",
     ]
-    
+
     for s in offset_datetime_strings:
         odt = fasttime.OffsetDateTime.parse(s)
         print(f"{s:45} -> {odt}")
@@ -87,11 +87,11 @@ def main():
     # 5. Round-trip: String -> Parse -> String
     print("5. Round-trip Parsing")
     print("-" * 40)
-    
+
     original = "2024-06-15T14:30:45.123456789+05:30"
     odt = fasttime.OffsetDateTime.parse(original)
     serialized = str(odt)
-    
+
     print(f"Original:   {original}")
     print(f"Parsed:     {odt}")
     print(f"Serialized: {serialized}")
@@ -101,14 +101,14 @@ def main():
     # 6. Error handling
     print("6. Error Handling")
     print("-" * 40)
-    
+
     invalid_strings = [
         ("2024-13-01", "Invalid month"),
         ("2024-02-30", "Invalid day for February"),
         ("25:00:00", "Invalid hour"),
         ("2024-01-01", "Missing time/timezone for DateTime"),
     ]
-    
+
     for s, reason in invalid_strings:
         try:
             if ":" in s and "-" not in s:
@@ -121,7 +121,7 @@ def main():
                 # Looks like a date
                 fasttime.Date.parse(s)
             print(f"✗ {s:20} - Should have failed ({reason})")
-        except ValueError as e:
+        except ValueError:
             print(f"✓ {s:20} - Correctly rejected: {reason}")
     print()
 
diff --git a/python/examples/timezones.py b/python/examples/timezones.py
index c8b09ee..49ece79 100644
--- a/python/examples/timezones.py
+++ b/python/examples/timezones.py
@@ -14,12 +14,12 @@ def main():
     # 1. Creating UTC Offsets
     print("1. Creating UTC Offsets")
     print("-" * 40)
-    
+
     utc = fasttime.UtcOffset.from_seconds(0)
     plus_five_thirty = fasttime.UtcOffset.from_hours_minutes(True, 5, 30)
     minus_eight = fasttime.UtcOffset.from_hours_minutes(False, 8, 0)
     plus_one = fasttime.UtcOffset.from_seconds(3600)
-    
+
     print(f"UTC:         {utc} ({utc.as_seconds()} seconds)")
     print(f"+05:30:      {plus_five_thirty} ({plus_five_thirty.as_seconds()} seconds)")
     print(f"-08:00:      {minus_eight} ({minus_eight.as_seconds()} seconds)")
@@ -31,10 +31,10 @@ def main():
     # 2. Creating OffsetDateTime from UTC
     print("2. Creating OffsetDateTime from UTC")
     print("-" * 40)
-    
+
     utc_dt = fasttime.DateTime.parse("2024-06-15T12:00:00Z")
     offset = fasttime.UtcOffset.from_hours_minutes(True, 5, 30)
-    
+
     odt = fasttime.OffsetDateTime.from_utc(utc_dt, offset)
     print(f"UTC DateTime:    {utc_dt}")
     print(f"With offset:     {odt}")
@@ -44,11 +44,11 @@ def main():
     # 3. Creating OffsetDateTime from Local Time
     print("3. Creating OffsetDateTime from Local Time")
     print("-" * 40)
-    
+
     date = fasttime.Date(2024, 6, 15)
     time = fasttime.Time(18, 0, 0)  # 6:00 PM local
     offset = fasttime.UtcOffset.from_hours_minutes(True, 5, 30)  # +05:30
-    
+
     odt = fasttime.OffsetDateTime.from_local(date, time, offset)
     print(f"Local Date:      {date}")
     print(f"Local Time:      {time}")
@@ -60,19 +60,19 @@ def main():
     # 4. Common Timezone Offsets
     print("4. Common Timezone Offsets")
     print("-" * 40)
-    
+
     common_offsets = [
         ("UTC", 0, 0, True),
-        ("EST", 5, 0, False),   # -05:00
-        ("PST", 8, 0, False),   # -08:00
-        ("CET", 1, 0, True),    # +01:00
-        ("IST", 5, 30, True),   # +05:30 (India)
-        ("JST", 9, 0, True),    # +09:00 (Japan)
+        ("EST", 5, 0, False),  # -05:00
+        ("PST", 8, 0, False),  # -08:00
+        ("CET", 1, 0, True),  # +01:00
+        ("IST", 5, 30, True),  # +05:30 (India)
+        ("JST", 9, 0, True),  # +09:00 (Japan)
     ]
-    
+
     date = fasttime.Date(2024, 6, 15)
     time = fasttime.Time(12, 0, 0)  # Noon local
-    
+
     for name, hours, minutes, positive in common_offsets:
         offset = fasttime.UtcOffset.from_hours_minutes(positive, hours, minutes)
         odt = fasttime.OffsetDateTime.from_local(date, time, offset)
@@ -82,19 +82,19 @@ def main():
     # 5. Converting Between Offsets
     print("5. Converting Between Offsets")
     print("-" * 40)
-    
+
     # Start with a time in New York (EST)
     ny_offset = fasttime.UtcOffset.from_hours_minutes(False, 5, 0)
     ny_date = fasttime.Date(2024, 6, 15)
     ny_time = fasttime.Time(14, 30, 0)  # 2:30 PM in NY
-    
+
     ny_dt = fasttime.OffsetDateTime.from_local(ny_date, ny_time, ny_offset)
     print(f"New York time:    {ny_dt}")
-    
+
     # Convert to UTC
     utc_dt = ny_dt.utc
     print(f"UTC time:         {utc_dt}")
-    
+
     # Convert to Tokyo (JST)
     tokyo_offset = fasttime.UtcOffset.from_hours_minutes(True, 9, 0)
     tokyo_dt = fasttime.OffsetDateTime.from_utc(utc_dt, tokyo_offset)
@@ -105,14 +105,14 @@ def main():
     # 6. Parsing RFC 3339 with Offsets
     print("6. Parsing RFC 3339 with Offsets")
     print("-" * 40)
-    
+
     rfc3339_examples = [
         "2024-06-15T12:00:00Z",
         "2024-06-15T12:00:00+00:00",
         "2024-06-15T12:00:00-05:00",
         "2024-06-15T12:00:00+05:30",
     ]
-    
+
     for s in rfc3339_examples:
         odt = fasttime.OffsetDateTime.parse(s)
         print(f"{s:35} -> {odt}")
@@ -122,11 +122,11 @@ def main():
     # 7. Duration with Offsets
     print("7. Duration with Offsets")
     print("-" * 40)
-    
+
     start = fasttime.OffsetDateTime.parse("2024-06-15T10:00:00+05:30")
     duration = fasttime.Duration.seconds(7200)  # 2 hours
     end = start.add_duration(duration)
-    
+
     print(f"Start:    {start}")
     print(f"Duration: {duration.total_seconds() / 3600} hours")
     print(f"End:      {end}")
@@ -136,18 +136,18 @@ def main():
     # 8. Comparing Across Offsets
     print("8. Comparing Across Offsets")
     print("-" * 40)
-    
+
     # 12:00 in New York
     ny = fasttime.OffsetDateTime.parse("2024-06-15T12:00:00-05:00")
     # 17:00 in UTC (same instant)
     utc = fasttime.OffsetDateTime.parse("2024-06-15T17:00:00Z")
     # 22:30 in India (same instant)
     india = fasttime.OffsetDateTime.parse("2024-06-15T22:30:00+05:30")
-    
+
     print(f"New York: {ny}")
     print(f"UTC:      {utc}")
     print(f"India:    {india}")
-    print(f"\nAll represent the same instant:")
+    print("\nAll represent the same instant:")
     print(f"NY == UTC:    {ny == utc}")
     print(f"UTC == India: {utc == india}")
     print(f"NY == India:  {ny == india}")
@@ -156,16 +156,16 @@ def main():
     # 9. Unix Timestamps with Offsets
     print("9. Unix Timestamps with Offsets")
     print("-" * 40)
-    
+
     odt = fasttime.OffsetDateTime.parse("2024-06-15T18:00:00+05:30")
     timestamp = odt.unix_timestamp()
     timestamp_nanos = odt.unix_timestamp_nanos()
-    
+
     print(f"OffsetDateTime:    {odt}")
     print(f"UTC equivalent:    {odt.utc}")
     print(f"Unix timestamp:    {timestamp}")
     print(f"Unix timestamp ns: {timestamp_nanos}")
-    
+
     # Convert back
     utc_dt = fasttime.DateTime.from_unix_timestamp(timestamp)
     print(f"From timestamp:    {utc_dt}")
diff --git a/python/examples/unix_timestamps.py b/python/examples/unix_timestamps.py
index fd76771..f237dab 100644
--- a/python/examples/unix_timestamps.py
+++ b/python/examples/unix_timestamps.py
@@ -14,12 +14,12 @@ def main():
     # 1. The Unix Epoch
     print("1. The Unix Epoch")
     print("-" * 40)
-    
+
     epoch = fasttime.DateTime.from_unix_timestamp(0)
     print(f"Unix epoch (timestamp 0): {epoch}")
     print(f"Date: {epoch.date}")
     print(f"Time: {epoch.time}")
-    
+
     epoch_date = fasttime.Date.from_days_since_unix_epoch(0)
     print(f"Epoch date: {epoch_date}")
     print()
@@ -27,11 +27,11 @@ def main():
     # 2. Converting to Unix Timestamps
     print("2. Converting to Unix Timestamps")
     print("-" * 40)
-    
+
     dt = fasttime.DateTime.parse("2024-06-15T12:30:45Z")
     timestamp = dt.unix_timestamp()
     timestamp_nanos = dt.unix_timestamp_nanos()
-    
+
     print(f"DateTime: {dt}")
     print(f"Unix timestamp (seconds): {timestamp}")
     print(f"Unix timestamp (nanos):   {timestamp_nanos}")
@@ -40,7 +40,7 @@ def main():
     # 3. Creating DateTimes from Timestamps
     print("3. Creating DateTimes from Timestamps")
     print("-" * 40)
-    
+
     # Various timestamps
     timestamps = [
         (0, "Unix epoch"),
@@ -48,7 +48,7 @@ def main():
         (1_700_000_000, "2023-11-14"),
         (2_000_000_000, "2033-05-18"),
     ]
-    
+
     for ts, description in timestamps:
         dt = fasttime.DateTime.from_unix_timestamp(ts)
         print(f"{ts:15} -> {dt} ({description})")
@@ -57,13 +57,13 @@ def main():
     # 4. Nanosecond Precision
     print("4. Nanosecond Precision")
     print("-" * 40)
-    
+
     # Create with nanoseconds
     dt1 = fasttime.DateTime.from_unix_timestamp(1_700_000_000, 0)
     dt2 = fasttime.DateTime.from_unix_timestamp(1_700_000_000, 123_456_789)
     dt3 = fasttime.DateTime.from_unix_timestamp(1_700_000_000, 999_999_999)
-    
-    print(f"Same second, different nanos:")
+
+    print("Same second, different nanos:")
     print(f"  {dt1} ({dt1.unix_timestamp_nanos()})")
     print(f"  {dt2} ({dt2.unix_timestamp_nanos()})")
     print(f"  {dt3} ({dt3.unix_timestamp_nanos()})")
@@ -72,12 +72,12 @@ def main():
     # 5. Negative Timestamps (Before 1970)
     print("5. Negative Timestamps (Before 1970)")
     print("-" * 40)
-    
+
     negative_timestamps = [
-        -86400,      # 1 day before epoch
+        -86400,  # 1 day before epoch
         -31_536_000,  # ~1 year before epoch
     ]
-    
+
     for ts in negative_timestamps:
         dt = fasttime.DateTime.from_unix_timestamp(ts)
         print(f"{ts:15} -> {dt}")
@@ -86,13 +86,13 @@ def main():
     # 6. Round-trip Conversion
     print("6. Round-trip Conversion")
     print("-" * 40)
-    
+
     original = fasttime.DateTime.parse("2024-06-15T14:30:45.123456789Z")
     timestamp = original.unix_timestamp()
     nanos = original.time.nanosecond
-    
+
     reconstructed = fasttime.DateTime.from_unix_timestamp(timestamp, nanos)
-    
+
     print(f"Original:      {original}")
     print(f"Timestamp:     {timestamp}")
     print(f"Nanoseconds:   {nanos}")
@@ -103,14 +103,14 @@ def main():
     # 7. Timestamp Arithmetic
     print("7. Timestamp Arithmetic")
     print("-" * 40)
-    
+
     dt = fasttime.DateTime.from_unix_timestamp(1_700_000_000)
     print(f"Base datetime: {dt}")
-    
+
     # Add various durations
     one_hour_later = dt.add_duration(fasttime.Duration.seconds(3600))
     one_day_later = dt.add_duration(fasttime.Duration.seconds(86400))
-    
+
     print(f"+1 hour: {one_hour_later} (ts: {one_hour_later.unix_timestamp()})")
     print(f"+1 day:  {one_day_later} (ts: {one_day_later.unix_timestamp()})")
     print()
@@ -118,13 +118,13 @@ def main():
     # 8. Timestamp Differences
     print("8. Timestamp Differences")
     print("-" * 40)
-    
+
     dt1 = fasttime.DateTime.from_unix_timestamp(1_700_000_000)
     dt2 = fasttime.DateTime.from_unix_timestamp(1_700_086_400)
-    
+
     diff = dt2.difference(dt1)
     ts_diff = dt2.unix_timestamp() - dt1.unix_timestamp()
-    
+
     print(f"DateTime 1:     {dt1} (ts: {dt1.unix_timestamp()})")
     print(f"DateTime 2:     {dt2} (ts: {dt2.unix_timestamp()})")
     print(f"Duration diff:  {diff.total_seconds()} seconds")
@@ -135,22 +135,24 @@ def main():
     # 9. OffsetDateTime Timestamps
     print("9. OffsetDateTime Timestamps")
     print("-" * 40)
-    
+
     # Different offsets, same instant
     utc_odt = fasttime.OffsetDateTime.parse("2024-06-15T12:00:00Z")
     ny_odt = fasttime.OffsetDateTime.parse("2024-06-15T07:00:00-05:00")
     tokyo_odt = fasttime.OffsetDateTime.parse("2024-06-15T21:00:00+09:00")
-    
+
     print(f"UTC:   {utc_odt} (ts: {utc_odt.unix_timestamp()})")
     print(f"NY:    {ny_odt} (ts: {ny_odt.unix_timestamp()})")
     print(f"Tokyo: {tokyo_odt} (ts: {tokyo_odt.unix_timestamp()})")
-    print(f"\nAll same instant: {utc_odt.unix_timestamp() == ny_odt.unix_timestamp() == tokyo_odt.unix_timestamp()}")
+    print(
+        f"\nAll same instant: {utc_odt.unix_timestamp() == ny_odt.unix_timestamp() == tokyo_odt.unix_timestamp()}"
+    )
     print()
 
     # 10. High-resolution Timing
     print("10. High-resolution Timing")
     print("-" * 40)
-    
+
     # Simulate high-precision measurements
     measurements = [
         fasttime.DateTime.from_unix_timestamp(1_700_000_000, 0),
@@ -158,23 +160,23 @@ def main():
         fasttime.DateTime.from_unix_timestamp(1_700_000_000, 200_000),
         fasttime.DateTime.from_unix_timestamp(1_700_000_000, 300_000),
     ]
-    
+
     print("High-resolution measurements:")
     for i, dt in enumerate(measurements):
         nanos = dt.unix_timestamp_nanos()
         print(f"  {i}: {dt} ({nanos} ns)")
-    
+
     # Calculate intervals
     print("\nIntervals:")
     for i in range(len(measurements) - 1):
         diff = measurements[i + 1].difference(measurements[i])
-        print(f"  {i} -> {i+1}: {diff.total_nanos()} ns")
+        print(f"  {i} -> {i + 1}: {diff.total_nanos()} ns")
     print()
 
     # 11. Common Timestamps
     print("11. Common Historical Timestamps")
     print("-" * 40)
-    
+
     historical = [
         (0, "Unix epoch"),
         (315_532_800, "Y2K preparation era (1980-01-01)"),
@@ -182,10 +184,10 @@ def main():
         (1_000_000_000, "Billennium"),
         (1_234_567_890, "Unix billionth second + change"),
     ]
-    
+
     for ts, desc in historical:
         dt = fasttime.DateTime.from_unix_timestamp(ts)
-        print(f"{ts:15} -> {dt:30} {desc}")
+        print(f"{ts:15} -> {dt!s:30} {desc}")
     print()
 
 
diff --git a/python/fasttime/__init__.py b/python/fasttime/__init__.py
index 1851aed..378863e 100644
--- a/python/fasttime/__init__.py
+++ b/python/fasttime/__init__.py
@@ -2,7 +2,27 @@
 fasttime - Fast UTC date/time library for Python, powered by Rust.
 """
 
-from .fasttime import *  # noqa: F403, F401
+from .fasttime import (
+    Date as Date,
+)
+from .fasttime import (
+    DateTime as DateTime,
+)
+from .fasttime import (
+    Duration as Duration,
+)
+from .fasttime import (
+    OffsetDateTime as OffsetDateTime,
+)
+from .fasttime import (
+    Time as Time,
+)
+from .fasttime import (
+    UtcOffset as UtcOffset,
+)
+from .fasttime import (
+    Weekday as Weekday,
+)
 
 __all__ = [
     "Weekday",
diff --git a/python/fasttime/__init__.pyi b/python/fasttime/__init__.pyi
index b4d22dc..eeaa807 100644
--- a/python/fasttime/__init__.pyi
+++ b/python/fasttime/__init__.pyi
@@ -1,272 +1,21 @@
-"""
-Type stubs for fasttime Python bindings.
-
-This file provides type hints for the fasttime module, which is
-implemented in Rust via PyO3.
-"""
-
-from typing import ClassVar
-
-class Weekday:
-    """Calendar weekday (ISO order, Monday = 1)."""
-    MONDAY: ClassVar[Weekday]
-    TUESDAY: ClassVar[Weekday]
-    WEDNESDAY: ClassVar[Weekday]
-    THURSDAY: ClassVar[Weekday]
-    FRIDAY: ClassVar[Weekday]
-    SATURDAY: ClassVar[Weekday]
-    SUNDAY: ClassVar[Weekday]
-    
-    def number_from_monday(self) -> int:
-        """Get the weekday number from Monday (1-7)."""
-        ...
-
-class Date:
-    """Gregorian calendar date (proleptic)."""
-    
-    def __init__(self, year: int, month: int, day: int) -> None:
-        """Create a new Date from year, month, and day."""
-        ...
-    
-    @property
-    def year(self) -> int:
-        """Year component."""
-        ...
-    
-    @property
-    def month(self) -> int:
-        """Month component (1-12)."""
-        ...
-    
-    @property
-    def day(self) -> int:
-        """Day component (1-31)."""
-        ...
-    
-    @classmethod
-    def from_days_since_unix_epoch(cls, days: int) -> Date:
-        """Create a Date from days since Unix epoch."""
-        ...
-    
-    def days_since_unix_epoch(self) -> int:
-        """Convert to days since Unix epoch."""
-        ...
-    
-    def weekday(self) -> Weekday:
-        """Get the weekday."""
-        ...
-    
-    def ordinal(self) -> int:
-        """Get the day of the year (1-366)."""
-        ...
-    
-    def add_days(self, days: int) -> Date:
-        """Add days to the date."""
-        ...
-    
-    @classmethod
-    def parse(cls, s: str) -> Date:
-        """Parse a date from ISO format (YYYY-MM-DD)."""
-        ...
-
-class Time:
-    """Time of day in nanoseconds since midnight."""
-    
-    def __init__(self, hour: int, minute: int, second: int, nanosecond: int = 0) -> None:
-        """Create a new Time."""
-        ...
-    
-    @property
-    def hour(self) -> int:
-        """Hour component (0-23)."""
-        ...
-    
-    @property
-    def minute(self) -> int:
-        """Minute component (0-59)."""
-        ...
-    
-    @property
-    def second(self) -> int:
-        """Second component (0-59)."""
-        ...
-    
-    @property
-    def nanosecond(self) -> int:
-        """Nanosecond component (0-999,999,999)."""
-        ...
-    
-    def seconds_since_midnight(self) -> int:
-        """Get total seconds since midnight."""
-        ...
-    
-    def nanos_since_midnight(self) -> int:
-        """Get total nanoseconds since midnight."""
-        ...
-    
-    @classmethod
-    def parse(cls, s: str) -> Time:
-        """Parse a time from ISO format."""
-        ...
-
-class Duration:
-    """Signed duration with nanosecond precision."""
-    
-    @classmethod
-    def seconds(cls, secs: int) -> Duration:
-        """Create a duration from seconds."""
-        ...
-    
-    @classmethod
-    def milliseconds(cls, ms: int) -> Duration:
-        """Create a duration from milliseconds."""
-        ...
-    
-    @classmethod
-    def microseconds(cls, us: int) -> Duration:
-        """Create a duration from microseconds."""
-        ...
-    
-    @classmethod
-    def nanoseconds(cls, ns: int) -> Duration:
-        """Create a duration from nanoseconds."""
-        ...
-    
-    def total_seconds(self) -> float:
-        """Get total seconds as a float."""
-        ...
-    
-    def total_nanos(self) -> int:
-        """Get total nanoseconds as an integer."""
-        ...
-    
-    def __add__(self, other: Duration) -> Duration: ...
-    def __sub__(self, other: Duration) -> Duration: ...
-    def __neg__(self) -> Duration: ...
-
-class DateTime:
-    """Combined UTC date and time."""
-    
-    def __init__(self, date: Date, time: Time) -> None:
-        """Create a DateTime from a Date and Time."""
-        ...
-    
-    @property
-    def date(self) -> Date:
-        """Date component."""
-        ...
-    
-    @property
-    def time(self) -> Time:
-        """Time component."""
-        ...
-    
-    @classmethod
-    def from_unix_timestamp(cls, secs: int, nanos: int = 0) -> DateTime:
-        """Create a DateTime from Unix timestamp."""
-        ...
-    
-    def unix_timestamp(self) -> int:
-        """Get Unix timestamp (seconds since Unix epoch)."""
-        ...
-    
-    def unix_timestamp_nanos(self) -> int:
-        """Get Unix timestamp in nanoseconds."""
-        ...
-    
-    def add_duration(self, dur: Duration) -> DateTime:
-        """Add a duration to this DateTime."""
-        ...
-    
-    def difference(self, other: DateTime) -> Duration:
-        """Calculate the difference between two DateTimes."""
-        ...
-    
-    @classmethod
-    def now_utc(cls) -> DateTime:
-        """Get the current UTC DateTime."""
-        ...
-    
-    @classmethod
-    def parse(cls, s: str) -> DateTime:
-        """Parse a DateTime from ISO 8601 / RFC 3339 UTC format."""
-        ...
-
-class UtcOffset:
-    """Fixed offset from UTC."""
-    
-    @classmethod
-    def from_seconds(cls, seconds: int) -> UtcOffset:
-        """Create a UtcOffset from total seconds."""
-        ...
-    
-    @classmethod
-    def from_hours_minutes(cls, sign_positive: bool, hours: int, minutes: int) -> UtcOffset:
-        """Create a UtcOffset from hours and minutes."""
-        ...
-    
-    def as_seconds(self) -> int:
-        """Get the offset as seconds."""
-        ...
-    
-    def is_utc(self) -> bool:
-        """Check if this is UTC (offset = 0)."""
-        ...
-
-class OffsetDateTime:
-    """Date-time with a fixed offset from UTC."""
-    
-    @classmethod
-    def from_utc(cls, utc: DateTime, offset: UtcOffset) -> OffsetDateTime:
-        """Create an OffsetDateTime from a UTC DateTime and offset."""
-        ...
-    
-    @classmethod
-    def from_local(cls, date: Date, time: Time, offset: UtcOffset) -> OffsetDateTime:
-        """Create an OffsetDateTime from local date, time, and offset."""
-        ...
-    
-    @property
-    def utc(self) -> DateTime:
-        """UTC datetime."""
-        ...
-    
-    @property
-    def offset(self) -> UtcOffset:
-        """Offset from UTC."""
-        ...
-    
-    def to_local(self) -> DateTime:
-        """Convert to local DateTime."""
-        ...
-    
-    def unix_timestamp(self) -> int:
-        """Get Unix timestamp (seconds since Unix epoch)."""
-        ...
-    
-    def unix_timestamp_nanos(self) -> int:
-        """Get Unix timestamp in nanoseconds."""
-        ...
-    
-    def add_duration(self, dur: Duration) -> OffsetDateTime:
-        """Add a duration."""
-        ...
-    
-    def difference(self, other: OffsetDateTime) -> Duration:
-        """Calculate the difference between two OffsetDateTimes."""
-        ...
-    
-    @classmethod
-    def parse(cls, s: str) -> OffsetDateTime:
-        """Parse an OffsetDateTime from RFC 3339 format."""
-        ...
-
-__all__ = [
-    "Weekday",
-    "Date",
-    "Time",
-    "Duration",
-    "DateTime",
-    "UtcOffset",
-    "OffsetDateTime",
-]
+from .fasttime import (
+    Date as Date,
+)
+from .fasttime import (
+    DateTime as DateTime,
+)
+from .fasttime import (
+    Duration as Duration,
+)
+from .fasttime import (
+    OffsetDateTime as OffsetDateTime,
+)
+from .fasttime import (
+    Time as Time,
+)
+from .fasttime import (
+    UtcOffset as UtcOffset,
+)
+from .fasttime import (
+    Weekday as Weekday,
+)
diff --git a/python/fasttime/fasttime.pyi b/python/fasttime/fasttime.pyi
new file mode 100644
index 0000000..27aaffa
--- /dev/null
+++ b/python/fasttime/fasttime.pyi
@@ -0,0 +1,307 @@
+"""
+Type stubs for fasttime Python bindings.
+
+This file provides type hints for the fasttime module, which is
+implemented in Rust via PyO3.
+"""
+
+from typing import ClassVar
+
+class Weekday:
+    """Calendar weekday (ISO order, Monday = 1)."""
+
+    MONDAY: ClassVar[Weekday]
+    TUESDAY: ClassVar[Weekday]
+    WEDNESDAY: ClassVar[Weekday]
+    THURSDAY: ClassVar[Weekday]
+    FRIDAY: ClassVar[Weekday]
+    SATURDAY: ClassVar[Weekday]
+    SUNDAY: ClassVar[Weekday]
+
+    def number_from_monday(self) -> int:
+        """Get the weekday number from Monday (1-7)."""
+        ...
+
+class Date:
+    def __lt__(self, other: Date) -> bool: ...
+    def __le__(self, other: Date) -> bool: ...
+    def __gt__(self, other: Date) -> bool: ...
+    def __ge__(self, other: Date) -> bool: ...
+
+    """Gregorian calendar date (proleptic)."""
+
+    def __init__(self, year: int, month: int, day: int) -> None:
+        """Create a new Date from year, month, and day."""
+        ...
+
+    @property
+    def year(self) -> int:
+        """Year component."""
+        ...
+
+    @property
+    def month(self) -> int:
+        """Month component (1-12)."""
+        ...
+
+    @property
+    def day(self) -> int:
+        """Day component (1-31)."""
+        ...
+
+    @classmethod
+    def from_days_since_unix_epoch(cls, days: int) -> Date:
+        """Create a Date from days since Unix epoch."""
+        ...
+
+    def days_since_unix_epoch(self) -> int:
+        """Convert to days since Unix epoch."""
+        ...
+
+    def weekday(self) -> Weekday:
+        """Get the weekday."""
+        ...
+
+    def ordinal(self) -> int:
+        """Get the day of the year (1-366)."""
+        ...
+
+    def add_days(self, days: int) -> Date:
+        """Add days to the date."""
+        ...
+
+    @classmethod
+    def parse(cls, s: str) -> Date:
+        """Parse a date from ISO format (YYYY-MM-DD)."""
+        ...
+
+class Time:
+    def __lt__(self, other: Time) -> bool: ...
+    def __le__(self, other: Time) -> bool: ...
+    def __gt__(self, other: Time) -> bool: ...
+    def __ge__(self, other: Time) -> bool: ...
+
+    """Time of day in nanoseconds since midnight."""
+
+    def __init__(
+        self, hour: int, minute: int, second: int, nanosecond: int = 0
+    ) -> None:
+        """Create a new Time."""
+        ...
+
+    @property
+    def hour(self) -> int:
+        """Hour component (0-23)."""
+        ...
+
+    @property
+    def minute(self) -> int:
+        """Minute component (0-59)."""
+        ...
+
+    @property
+    def second(self) -> int:
+        """Second component (0-59)."""
+        ...
+
+    @property
+    def nanosecond(self) -> int:
+        """Nanosecond component (0-999,999,999)."""
+        ...
+
+    def seconds_since_midnight(self) -> int:
+        """Get total seconds since midnight."""
+        ...
+
+    def nanos_since_midnight(self) -> int:
+        """Get total nanoseconds since midnight."""
+        ...
+
+    @classmethod
+    def parse(cls, s: str) -> Time:
+        """Parse a time from ISO format."""
+        ...
+
+class Duration:
+    def __lt__(self, other: Duration) -> bool: ...
+    def __le__(self, other: Duration) -> bool: ...
+    def __gt__(self, other: Duration) -> bool: ...
+    def __ge__(self, other: Duration) -> bool: ...
+
+    """Signed duration with nanosecond precision."""
+
+    @classmethod
+    def seconds(cls, secs: int) -> Duration:
+        """Create a duration from seconds."""
+        ...
+
+    @classmethod
+    def milliseconds(cls, ms: int) -> Duration:
+        """Create a duration from milliseconds."""
+        ...
+
+    @classmethod
+    def microseconds(cls, us: int) -> Duration:
+        """Create a duration from microseconds."""
+        ...
+
+    @classmethod
+    def nanoseconds(cls, ns: int) -> Duration:
+        """Create a duration from nanoseconds."""
+        ...
+
+    def total_seconds(self) -> float:
+        """Get total seconds as a float."""
+        ...
+
+    def total_nanos(self) -> int:
+        """Get total nanoseconds as an integer."""
+        ...
+
+    def __add__(self, other: Duration) -> Duration: ...
+    def __sub__(self, other: Duration) -> Duration: ...
+    def __neg__(self) -> Duration: ...
+
+class DateTime:
+    def __lt__(self, other: DateTime) -> bool: ...
+    def __le__(self, other: DateTime) -> bool: ...
+    def __gt__(self, other: DateTime) -> bool: ...
+    def __ge__(self, other: DateTime) -> bool: ...
+
+    """Combined UTC date and time."""
+
+    def __init__(self, date: Date, time: Time) -> None:
+        """Create a DateTime from a Date and Time."""
+        ...
+
+    @property
+    def date(self) -> Date:
+        """Date component."""
+        ...
+
+    @property
+    def time(self) -> Time:
+        """Time component."""
+        ...
+
+    @classmethod
+    def from_unix_timestamp(cls, secs: int, nanos: int = 0) -> DateTime:
+        """Create a DateTime from Unix timestamp."""
+        ...
+
+    def unix_timestamp(self) -> int:
+        """Get Unix timestamp (seconds since Unix epoch)."""
+        ...
+
+    def unix_timestamp_nanos(self) -> int:
+        """Get Unix timestamp in nanoseconds."""
+        ...
+
+    def add_duration(self, dur: Duration) -> DateTime:
+        """Add a duration to this DateTime."""
+        ...
+
+    def difference(self, other: DateTime) -> Duration:
+        """Calculate the difference between two DateTimes."""
+        ...
+
+    @classmethod
+    def now_utc(cls) -> DateTime:
+        """Get the current UTC DateTime."""
+        ...
+
+    @classmethod
+    def parse(cls, s: str) -> DateTime:
+        """Parse a DateTime from ISO 8601 / RFC 3339 UTC format."""
+        ...
+
+class UtcOffset:
+    def __lt__(self, other: UtcOffset) -> bool: ...
+    def __le__(self, other: UtcOffset) -> bool: ...
+    def __gt__(self, other: UtcOffset) -> bool: ...
+    def __ge__(self, other: UtcOffset) -> bool: ...
+
+    """Fixed offset from UTC."""
+
+    @classmethod
+    def from_seconds(cls, seconds: int) -> UtcOffset:
+        """Create a UtcOffset from total seconds."""
+        ...
+
+    @classmethod
+    def from_hours_minutes(
+        cls, sign_positive: bool, hours: int, minutes: int
+    ) -> UtcOffset:
+        """Create a UtcOffset from hours and minutes."""
+        ...
+
+    def as_seconds(self) -> int:
+        """Get the offset as seconds."""
+        ...
+
+    def is_utc(self) -> bool:
+        """Check if this is UTC (offset = 0)."""
+        ...
+
+class OffsetDateTime:
+    def __lt__(self, other: OffsetDateTime) -> bool: ...
+    def __le__(self, other: OffsetDateTime) -> bool: ...
+    def __gt__(self, other: OffsetDateTime) -> bool: ...
+    def __ge__(self, other: OffsetDateTime) -> bool: ...
+
+    """Date-time with a fixed offset from UTC."""
+
+    @classmethod
+    def from_utc(cls, utc: DateTime, offset: UtcOffset) -> OffsetDateTime:
+        """Create an OffsetDateTime from a UTC DateTime and offset."""
+        ...
+
+    @classmethod
+    def from_local(cls, date: Date, time: Time, offset: UtcOffset) -> OffsetDateTime:
+        """Create an OffsetDateTime from local date, time, and offset."""
+        ...
+
+    @property
+    def utc(self) -> DateTime:
+        """UTC datetime."""
+        ...
+
+    @property
+    def offset(self) -> UtcOffset:
+        """Offset from UTC."""
+        ...
+
+    def to_local(self) -> DateTime:
+        """Convert to local DateTime."""
+        ...
+
+    def unix_timestamp(self) -> int:
+        """Get Unix timestamp (seconds since Unix epoch)."""
+        ...
+
+    def unix_timestamp_nanos(self) -> int:
+        """Get Unix timestamp in nanoseconds."""
+        ...
+
+    def add_duration(self, dur: Duration) -> OffsetDateTime:
+        """Add a duration."""
+        ...
+
+    def difference(self, other: OffsetDateTime) -> Duration:
+        """Calculate the difference between two OffsetDateTimes."""
+        ...
+
+    @classmethod
+    def parse(cls, s: str) -> OffsetDateTime:
+        """Parse an OffsetDateTime from RFC 3339 format."""
+        ...
+
+__all__ = [
+    "Weekday",
+    "Date",
+    "Time",
+    "Duration",
+    "DateTime",
+    "UtcOffset",
+    "OffsetDateTime",
+]
diff --git a/python/tests/test_fasttime.py b/python/tests/test_fasttime.py
index 4764f34..da7740f 100644
--- a/python/tests/test_fasttime.py
+++ b/python/tests/test_fasttime.py
@@ -2,8 +2,8 @@
 Tests for the fasttime Python bindings.
 """
 
-import pytest
 import fasttime
+import pytest
 
 
 def test_date_creation():
@@ -34,7 +34,7 @@ def test_date_invalid():
     """Test that invalid dates raise errors."""
     with pytest.raises(ValueError):
         fasttime.Date(2024, 13, 1)  # Invalid month
-    
+
     with pytest.raises(ValueError):
         fasttime.Date(2024, 2, 30)  # Invalid day for February
 
@@ -50,7 +50,7 @@ def test_date_ordinal():
     """Test ordinal (day of year) calculation."""
     date = fasttime.Date(2024, 1, 1)
     assert date.ordinal() == 1
-    
+
     date = fasttime.Date(2024, 12, 31)
     assert date.ordinal() == 366  # 2024 is a leap year
 
@@ -68,7 +68,7 @@ def test_date_comparison():
     """Test date comparisons."""
     date1 = fasttime.Date(2024, 1, 1)
     date2 = fasttime.Date(2024, 12, 31)
-    
+
     assert date1 < date2
     assert date1 <= date2
     assert date2 > date1
@@ -82,10 +82,10 @@ def test_date_hash():
     date1 = fasttime.Date(2024, 1, 1)
     date2 = fasttime.Date(2024, 1, 1)
     date3 = fasttime.Date(2024, 12, 31)
-    
+
     assert hash(date1) == hash(date2)
     assert hash(date1) != hash(date3)
-    
+
     # Test in sets
     dates = {date1, date2, date3}
     assert len(dates) == 2
@@ -113,7 +113,7 @@ def test_time_invalid():
     """Test that invalid times raise errors."""
     with pytest.raises(ValueError):
         fasttime.Time(25, 0, 0)  # Invalid hour
-    
+
     with pytest.raises(ValueError):
         fasttime.Time(0, 60, 0)  # Invalid minute
 
@@ -123,7 +123,7 @@ def test_datetime_creation():
     date = fasttime.Date(2024, 6, 15)
     time = fasttime.Time(12, 30, 45)
     dt = fasttime.DateTime(date, time)
-    
+
     assert dt.date == date
     assert dt.time == time
 
@@ -156,7 +156,7 @@ def test_datetime_add_duration():
     """Test adding durations to datetimes."""
     dt = fasttime.DateTime.parse("2024-01-01T00:00:00Z")
     one_hour = fasttime.Duration.seconds(3600)
-    
+
     later = dt.add_duration(one_hour)
     assert later.time.hour == 1
 
@@ -165,7 +165,7 @@ def test_datetime_difference():
     """Test calculating differences between datetimes."""
     dt1 = fasttime.DateTime.parse("2024-01-01T00:00:00Z")
     dt2 = fasttime.DateTime.parse("2024-01-01T01:00:00Z")
-    
+
     diff = dt2.difference(dt1)
     assert diff.total_seconds() == 3600
 
@@ -174,7 +174,7 @@ def test_duration_creation():
     """Test creating durations."""
     seconds = fasttime.Duration.seconds(60)
     millis = fasttime.Duration.milliseconds(1000)
-    
+
     assert seconds.total_seconds() == 60
     assert millis.total_seconds() == 1
 
@@ -183,11 +183,11 @@ def test_duration_arithmetic():
     """Test duration arithmetic."""
     dur1 = fasttime.Duration.seconds(10)
     dur2 = fasttime.Duration.seconds(5)
-    
+
     total = dur1 + dur2
     diff = dur1 - dur2
     neg = -dur1
-    
+
     assert total.total_seconds() == 15
     assert diff.total_seconds() == 5
     assert neg.total_seconds() == -10
@@ -197,7 +197,7 @@ def test_duration_comparison():
     """Test duration comparisons."""
     short = fasttime.Duration.seconds(10)
     long = fasttime.Duration.seconds(100)
-    
+
     assert short < long
     assert short <= long
     assert long > short
@@ -210,7 +210,7 @@ def test_utc_offset_creation():
     """Test creating UTC offsets."""
     offset = fasttime.UtcOffset.from_hours_minutes(True, 5, 30)
     assert offset.as_seconds() == 5 * 3600 + 30 * 60
-    
+
     offset_neg = fasttime.UtcOffset.from_hours_minutes(False, 8, 0)
     assert offset_neg.as_seconds() == -8 * 3600
 
@@ -219,7 +219,7 @@ def test_utc_offset_is_utc():
     """Test checking if offset is UTC."""
     utc = fasttime.UtcOffset.from_seconds(0)
     not_utc = fasttime.UtcOffset.from_hours_minutes(True, 5, 0)
-    
+
     assert utc.is_utc()
     assert not not_utc.is_utc()
 
@@ -229,7 +229,7 @@ def test_offset_datetime_from_local():
     date = fasttime.Date(2024, 6, 15)
     time = fasttime.Time(18, 0, 0)
     offset = fasttime.UtcOffset.from_hours_minutes(True, 5, 30)
-    
+
     odt = fasttime.OffsetDateTime.from_local(date, time, offset)
     assert odt.offset == offset
 
@@ -244,7 +244,7 @@ def test_offset_datetime_to_local():
     """Test converting offset datetime to local."""
     odt = fasttime.OffsetDateTime.parse("2024-06-15T12:00:00Z")
     local = odt.to_local()
-    
+
     assert local.date.year == 2024
     assert local.date.month == 6
     assert local.date.day == 15
@@ -255,7 +255,7 @@ def test_round_trip_date():
     original = fasttime.Date(2024, 6, 15)
     days = original.days_since_unix_epoch()
     reconstructed = fasttime.Date.from_days_since_unix_epoch(days)
-    
+
     assert original == reconstructed
 
 
@@ -265,7 +265,7 @@ def test_round_trip_datetime():
     timestamp = original.unix_timestamp()
     nanos = original.time.nanosecond
     reconstructed = fasttime.DateTime.from_unix_timestamp(timestamp, nanos)
-    
+
     assert original == reconstructed
 
 
@@ -274,5 +274,56 @@ def test_round_trip_offset_datetime():
     original = "2024-06-15T12:00:00+05:30"
     odt = fasttime.OffsetDateTime.parse(original)
     serialized = str(odt)
-    
+
     assert original == serialized
+
+
+@pytest.mark.parametrize(
+    "value, text, representation",
+    [
+        (fasttime.Weekday.MONDAY, "Monday", "Monday"),
+        (
+            fasttime.Date(-2147483648, 1, 1),
+            "-2147483648-01-01",
+            "Date(year=-2147483648, month=1, day=1)",
+        ),
+        (
+            fasttime.Date(2147483647, 12, 31),
+            "2147483647-12-31",
+            "Date(year=2147483647, month=12, day=31)",
+        ),
+        (
+            fasttime.Time(23, 59, 59, nanosecond=999999999),
+            "23:59:59.999999999",
+            "Time(hour=23, minute=59, second=59, nanosecond=999999999)",
+        ),
+        (
+            fasttime.Duration.nanoseconds(-(2**127)),
+            f"Duration({-(2**127)} ns)",
+            f"Duration.nanoseconds({-(2**127)})",
+        ),
+        (
+            fasttime.Duration.nanoseconds(2**127 - 1),
+            f"Duration({2**127 - 1} ns)",
+            f"Duration.nanoseconds({2**127 - 1})",
+        ),
+        (
+            fasttime.DateTime.parse("2024-06-15T12:30:45.123456789Z"),
+            "2024-06-15T12:30:45.123456789Z",
+            "DateTime.parse('2024-06-15T12:30:45.123456789Z')",
+        ),
+        (
+            fasttime.UtcOffset.from_seconds(-86399),
+            "-23:59",
+            "UtcOffset.from_seconds(-86399)",
+        ),
+        (
+            fasttime.OffsetDateTime.parse("2024-06-15T12:30:45.123456789+05:30"),
+            "2024-06-15T12:30:45.123456789+05:30",
+            "OffsetDateTime.parse('2024-06-15T12:30:45.123456789+05:30')",
+        ),
+    ],
+)
+def test_string_representations(value, text, representation):
+    assert str(value) == text
+    assert repr(value) == representation
diff --git a/src/lib.rs b/src/lib.rs
index f9e41d5..30cfe51 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -16,6 +16,19 @@
 //!   - `OffsetDateTime`: `YYYY-MM-DDTHH:MM:SS[.fffffffff][Z|±HH:MM]` (RFC 3339 subset).
 //! - `DateTime::now_utc()` when the `std` feature is enabled.
 //!
+//! ## Allocation behavior
+//!
+//! Rust parsing borrows the input string and returns inline `Copy` values;
+//! calendar arithmetic and timestamp conversion do not allocate. `Display`
+//! writes directly to the supplied formatter. Use `core::fmt::Write` with a
+//! caller-owned buffer to format without allocating; `to_string()` and
+//! `format!()` allocate their owned output.
+//!
+//! Python `str()` and `repr()` format through a fixed stack buffer, avoiding
+//! an intermediate Rust `String`. The resulting Python Unicode object still
+//! allocates and copies the formatted bytes. Python object construction and
+//! exceptions are outside the allocation-free Rust API guarantee.
+//!
 //! ## Python Bindings
 //!
 //! When built with the `python` feature, this crate provides Python bindings via `PyO3`.
diff --git a/src/python.rs b/src/python.rs
index 7eab42e..f479ca7 100644
--- a/src/python.rs
+++ b/src/python.rs
@@ -5,12 +5,44 @@
 // backticks around Python type names would leak into `help()` output.
 #![allow(clippy::doc_markdown)]
 
+use core::fmt::{self, Write};
 use pyo3::exceptions::PyValueError;
 use pyo3::prelude::*;
-use pyo3::types::PyType;
+use pyo3::types::{PyString, PyType};
 
 use crate::{Date, DateTime, Duration, OffsetDateTime, Time, UtcOffset, Weekday as RustWeekday};
 
+// All built-in representations fit in 128 bytes, including i32 years and
+// i128 durations. Keep formatting on the stack; only the returned Python
+// Unicode object needs a heap allocation.
+struct FormatBuffer {
+    bytes: [u8; 128],
+    len: usize,
+}
+
+impl Write for FormatBuffer {
+    fn write_str(&mut self, value: &str) -> fmt::Result {
+        let end = self.len.checked_add(value.len()).ok_or(fmt::Error)?;
+        let output = self.bytes.get_mut(self.len..end).ok_or(fmt::Error)?;
+        output.copy_from_slice(value.as_bytes());
+        self.len = end;
+        Ok(())
+    }
+}
+
+fn python_string<'py>(py: Python<'py>, args: fmt::Arguments<'_>) -> PyResult<Bound<'py, PyString>> {
+    let mut buffer = FormatBuffer {
+        bytes: [0; 128],
+        len: 0,
+    };
+    buffer
+        .write_fmt(args)
+        .map_err(|_| PyValueError::new_err("Representation exceeds formatting buffer"))?;
+    let text = core::str::from_utf8(&buffer.bytes[..buffer.len])
+        .map_err(|_| PyValueError::new_err("Invalid UTF-8 in representation"))?;
+    Ok(PyString::new(py, text))
+}
+
 // ===== Weekday =====
 
 #[pyclass(name = "Weekday", module = "fasttime", from_py_object)]
@@ -40,12 +72,12 @@ impl PyWeekday {
         self.0.number_from_monday()
     }
 
-    fn __repr__(&self) -> String {
-        format!("{:?}", self.0)
+    fn __repr__<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyString>> {
+        python_string(py, format_args!("{:?}", self.0))
     }
 
-    fn __str__(&self) -> String {
-        format!("{:?}", self.0)
+    fn __str__<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyString>> {
+        python_string(py, format_args!("{:?}", self.0))
     }
 }
 
@@ -163,14 +195,17 @@ impl PyDate {
             .map_err(|e| PyValueError::new_err(format!("Invalid date string: {e:?}")))
     }
 
-    fn __str__(&self) -> String {
-        self.0.to_string()
+    fn __str__<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyString>> {
+        python_string(py, format_args!("{}", self.0))
     }
 
-    fn __repr__(&self) -> String {
-        format!(
-            "Date(year={}, month={}, day={})",
-            self.0.year, self.0.month, self.0.day
+    fn __repr__<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyString>> {
+        python_string(
+            py,
+            format_args!(
+                "Date(year={}, month={}, day={})",
+                self.0.year, self.0.month, self.0.day
+            ),
         )
     }
 
@@ -277,14 +312,17 @@ impl PyTime {
             .map_err(|e| PyValueError::new_err(format!("Invalid time string: {e:?}")))
     }
 
-    fn __str__(&self) -> String {
-        self.0.to_string()
+    fn __str__<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyString>> {
+        python_string(py, format_args!("{}", self.0))
     }
 
-    fn __repr__(&self) -> String {
-        format!(
-            "Time(hour={}, minute={}, second={}, nanosecond={})",
-            self.0.hour, self.0.minute, self.0.second, self.0.nanosecond
+    fn __repr__<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyString>> {
+        python_string(
+            py,
+            format_args!(
+                "Time(hour={}, minute={}, second={}, nanosecond={})",
+                self.0.hour, self.0.minute, self.0.second, self.0.nanosecond
+            ),
         )
     }
 
@@ -369,12 +407,15 @@ impl PyDuration {
         PyDuration(-self.0)
     }
 
-    fn __str__(&self) -> String {
-        format!("Duration({} ns)", self.0.total_nanos())
+    fn __str__<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyString>> {
+        python_string(py, format_args!("Duration({} ns)", self.0.total_nanos()))
     }
 
-    fn __repr__(&self) -> String {
-        format!("Duration.nanoseconds({})", self.0.total_nanos())
+    fn __repr__<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyString>> {
+        python_string(
+            py,
+            format_args!("Duration.nanoseconds({})", self.0.total_nanos()),
+        )
     }
 
     fn __richcmp__(&self, other: &Self, op: pyo3::basic::CompareOp) -> bool {
@@ -528,12 +569,12 @@ impl PyDateTime {
         })
     }
 
-    fn __str__(&self) -> String {
-        self.0.to_string()
+    fn __str__<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyString>> {
+        python_string(py, format_args!("{}", self.0))
     }
 
-    fn __repr__(&self) -> String {
-        format!("DateTime.parse('{}')", self.0)
+    fn __repr__<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyString>> {
+        python_string(py, format_args!("DateTime.parse('{}')", self.0))
     }
 
     fn __richcmp__(&self, other: &Self, op: pyo3::basic::CompareOp) -> bool {
@@ -620,12 +661,15 @@ impl PyUtcOffset {
         self.0.is_utc()
     }
 
-    fn __str__(&self) -> String {
-        self.0.to_string()
+    fn __str__<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyString>> {
+        python_string(py, format_args!("{}", self.0))
     }
 
-    fn __repr__(&self) -> String {
-        format!("UtcOffset.from_seconds({})", self.0.as_seconds())
+    fn __repr__<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyString>> {
+        python_string(
+            py,
+            format_args!("UtcOffset.from_seconds({})", self.0.as_seconds()),
+        )
     }
 
     fn __richcmp__(&self, other: &Self, op: pyo3::basic::CompareOp) -> bool {
@@ -785,12 +829,12 @@ impl PyOffsetDateTime {
             })
     }
 
-    fn __str__(&self) -> String {
-        self.0.to_string()
+    fn __str__<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyString>> {
+        python_string(py, format_args!("{}", self.0))
     }
 
-    fn __repr__(&self) -> String {
-        format!("OffsetDateTime.parse('{}')", self.0)
+    fn __repr__<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyString>> {
+        python_string(py, format_args!("OffsetDateTime.parse('{}')", self.0))
     }
 
     fn __richcmp__(&self, other: &Self, op: pyo3::basic::CompareOp) -> bool {
diff --git a/tests/allocations.rs b/tests/allocations.rs
new file mode 100644
index 0000000..2c29d75
--- /dev/null
+++ b/tests/allocations.rs
@@ -0,0 +1,91 @@
+//! Guard the allocation-free Rust parsing, arithmetic and formatting paths.
+use fasttime::{Date, DateTime, Duration, OffsetDateTime, Time};
+use std::alloc::{GlobalAlloc, Layout, System};
+use std::cell::Cell;
+use std::fmt::{self, Write};
+use std::hint::black_box;
+
+thread_local! {
+    static COUNT: Cell<Option<usize>> = const { Cell::new(None) };
+}
+
+struct CountingAllocator;
+
+fn record() {
+    let _ = COUNT.try_with(|count| {
+        if let Some(value) = count.get() {
+            count.set(Some(value + 1));
+        }
+    });
+}
+
+// SAFETY: all operations delegate unchanged layouts and pointers to System.
+unsafe impl GlobalAlloc for CountingAllocator {
+    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+        record();
+        unsafe { System.alloc(layout) }
+    }
+    unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
+        record();
+        unsafe { System.alloc_zeroed(layout) }
+    }
+    unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, size: usize) -> *mut u8 {
+        record();
+        unsafe { System.realloc(ptr, layout, size) }
+    }
+    unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
+        unsafe { System.dealloc(ptr, layout) }
+    }
+}
+
+#[global_allocator]
+static ALLOCATOR: CountingAllocator = CountingAllocator;
+
+struct Buffer([u8; 128], usize);
+impl Write for Buffer {
+    fn write_str(&mut self, text: &str) -> fmt::Result {
+        let end = self.1 + text.len();
+        self.0
+            .get_mut(self.1..end)
+            .ok_or(fmt::Error)?
+            .copy_from_slice(text.as_bytes());
+        self.1 = end;
+        Ok(())
+    }
+}
+
+#[test]
+fn rust_hot_paths_do_not_allocate() {
+    // Positive control proves this thread's allocator instrumentation is active.
+    COUNT.with(|count| count.set(Some(0)));
+    let allocation = black_box(Box::new(42));
+    assert!(COUNT.with(|count| count.replace(None).unwrap()) > 0);
+    drop(allocation);
+
+    COUNT.with(|count| count.set(Some(0)));
+    for input in ["2024-06-15", "-2147483648-01-01", "2147483647-12-31"] {
+        let date = black_box(input).parse::<Date>().unwrap();
+        let mut buffer = Buffer([0; 128], 0);
+        write!(buffer, "{date}").unwrap();
+        black_box(buffer);
+    }
+    let time = black_box("12:30:45.123456789").parse::<Time>().unwrap();
+    let dt = black_box("2024-06-15T12:30:45.123456789Z")
+        .parse::<DateTime>()
+        .unwrap();
+    let offset = black_box("2024-06-15T12:30:45.123456789+05:30")
+        .parse::<OffsetDateTime>()
+        .unwrap();
+    for _ in 0..100 {
+        black_box(DateTime::from_unix_timestamp(dt.unix_timestamp(), 123456789).unwrap());
+        black_box(dt.add_duration(Duration::seconds(1)).unwrap());
+        black_box(offset.to_local().unwrap());
+        let mut buffer = Buffer([0; 128], 0);
+        write!(buffer, "{time} {dt} {offset}").unwrap();
+        black_box(buffer);
+    }
+    let _ = black_box("invalid".parse::<Date>());
+    let _ = black_box("invalid".parse::<Time>());
+    let allocations = COUNT.with(|count| count.replace(None).unwrap());
+    assert_eq!(allocations, 0);
+}