fix(parser): preserve sign for UTC/GMT/Z offset notation#1479
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BlocksecPHD wants to merge 3 commits intodateutil:masterfrom
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fix(parser): preserve sign for UTC/GMT/Z offset notation#1479BlocksecPHD wants to merge 3 commits intodateutil:masterfrom
BlocksecPHD wants to merge 3 commits intodateutil:masterfrom
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added 3 commits
April 9, 2026 05:10
Previously, UTC/GMT/Z followed by +/- offset incorrectly used POSIX convention reversal, causing 'UTC-4' to be parsed as +04:00 instead of -04:00. For timezone abbreviations like 'BRST+3', the POSIX convention is correct (the timezone is UTC-3). But for UTC offset notation like 'UTC-4', the sign should be literal (UTC minus 4 hours). This fix distinguishes between UTC zone names (UTC, GMT, Z) and other timezone abbreviations, preserving the literal sign for the former while keeping POSIX convention for the latter. Fixes dateutil#1478
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Problem
When parsing datetime strings like
'2026-03-11 14:32:45 UTC-4', the parser incorrectly reversed the offset sign, resulting in+04:00instead of the expected-04:00.Root Cause
The parser applied POSIX timezone convention to UTC zone names (UTC, GMT, Z). In POSIX,
EST5means the timezone is UTC-5 (not UTC+5), andGMT+3would mean UTC-3. However, modern UTC offset notation like'UTC-4'should mean UTC minus 4 hours literally, not POSIX convention.Fix
This PR distinguishes between UTC zone names (UTC, GMT, Z) and other timezone abbreviations:
'UTC-4'→-04:00)Test Cases
Added regression test
test_utc_offset_not_reversedcovering various UTC/GMT/Z offset combinations.Fixes: #1478