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Fix Timestamp.from_datetime returning wrong value for pre-epoch datetimes#662
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bysiber wants to merge 1 commit intomsgpack:main from
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Fix Timestamp.from_datetime returning wrong value for pre-epoch datetimes #662bysiber wants to merge 1 commit intomsgpack:main from
bysiber wants to merge 1 commit intomsgpack:main from
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int() truncates towards zero, so for pre-epoch datetimes with non-zero microseconds the seconds component gets the wrong value. For example, datetime(1969, 12, 31, 23, 59, 59, 500000, UTC) has timestamp -0.5, but int(-0.5) == 0, producing Timestamp(0, 500000000) (+0.5s after epoch) instead of Timestamp(-1, 500000000) (-0.5s before epoch). Use floor division (// 1) instead, consistent with from_unix().
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Timestamp.from_datetime()usesint(dt.timestamp())to compute the seconds component, butint()truncates towards zero. For pre-epoch datetimes with non-zero microseconds, this produces the wrong value:The sign of the time gets flipped.
from_unix()already handles this correctly using floor division (int(unix_sec // 1)). This change makesfrom_datetime()consistent.