Fix from_timestamp for negative timestamps before epoch#962
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parinporecha wants to merge 3 commits intopython-pendulum:masterfrom
Draft
Fix from_timestamp for negative timestamps before epoch#962parinporecha wants to merge 3 commits intopython-pendulum:masterfrom
parinporecha wants to merge 3 commits intopython-pendulum:masterfrom
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On Windows (and potentially other platforms), datetime.fromtimestamp raises OSError for timestamps earlier than a platform-specific minimum around -43200 (12h before the Unix epoch). This catches the OSError and falls back to computing from the epoch datetime with a timedelta. Adds tests for negative timestamps with UTC, explicit timezone, and microsecond precision.
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Problem
pendulum.from_timestamp()raises on some platforms for timestamps earlier than approximately 12 hours before the Unix epoch (for example-43201).Depending on the platform and Python build, the stdlib timestamp constructors can raise either
OSErrororOverflowErrorfor these values.The same underlying limitation also affects the public classmethods:
pendulum.DateTime.fromtimestamp()pendulum.DateTime.utcfromtimestamp()Reported in issue #956.
Reproduction
On some platforms the same call raises
OverflowErrorinstead.Fix
Catch
(OSError, OverflowError)from the stdlib timestamp constructors and fall back to computing the result from a fixed Unix epoch plus atimedelta.This PR covers:
pendulum.from_timestamp()pendulum.DateTime.fromtimestamp()pendulum.DateTime.utcfromtimestamp()The fallback preserves microseconds and keeps timezone conversion behavior intact.
Tests
Added and updated tests for:
pendulum.from_timestamp()DateTime.fromtimestamp()DateTime.utcfromtimestamp()OSErrorandOverflowErrorfallback pathsTargeted tests run locally:
PYTHONPATH=src pytest tests/datetime/test_create_from_timestamp.py -q PYTHONPATH=src pytest tests/datetime/test_behavior.py -k 'test_fromtimestamp_falls_back_for_negative_timestamp or test_utcfromtimestamp_falls_back_for_negative_timestamp or test_fromtimestamp or test_utcfromtimestamp' -qThe full suite was not run in this environment because unrelated test dependencies are missing (
time_machine,tzdata).