date: re-zone trailing TZ abbreviation input to local timezone#12327
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sylvestre merged 1 commit intoMay 16, 2026
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The dedicated abbreviation-aware path `try_parse_with_abbreviation` in
`src/uu/date/src/date.rs` returned a `Zoned` in the input abbreviation
timezone (e.g. `-05` for `EST`). The generic `parse_datetime` fallback
already re-zones to `now.time_zone()` for display, so identical inputs
took two divergent code paths and only one matched GNU `date`.
GNU treats a trailing TZ abbreviation as describing the *input*
timezone; the output is always re-zoned into the local zone (or UTC
under `-u`). For example, under `TZ=UTC`:
$ date -d "2024-01-01 EST" # GNU
Mon Jan 1 05:00:00 UTC 2024
uutils previously emitted `Mon Jan 1 00:00:00 -05 2024`.
Convert the parsed instant to `now.time_zone()` before returning,
matching the fallback path and GNU’s behavior. `-u` still works
because `now` is already zoned to UTC in that case (date.rs:362),
and the final output stage still applies `with_time_zone(TimeZone::UTC)`
when `settings.utc` is set.
Un-ignores the existing regression test for this issue.
Fixes uutils/parse_datetime#281.
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GNU testsuite comparison: |
Merging this PR will improve performance by 13.71%
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| Mode | Benchmark | BASE |
HEAD |
Efficiency | |
|---|---|---|---|---|---|
| ⚡ | Simulation | ls_recursive_balanced_tree[(6, 4, 15)] |
50.9 ms | 48.9 ms | +4.01% |
| ⚡ | Memory | cp_recursive_deep_tree[(120, 4)] |
699.2 KB | 562.5 KB | +24.31% |
Tip
Curious why this is faster? Comment @codspeedbot explain why this is faster on this PR, or directly use the CodSpeed MCP with your agent.
Comparing 0xSoftBoi:fix/281-trailing-tz-abbrev-rezones (3783654) with main (d09f351)
Footnotes
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46 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩
Contributor
|
nice, thanks |
nonontb
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to nonontb/coreutils
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May 28, 2026
…s#12327) The dedicated abbreviation-aware path `try_parse_with_abbreviation` in `src/uu/date/src/date.rs` returned a `Zoned` in the input abbreviation timezone (e.g. `-05` for `EST`). The generic `parse_datetime` fallback already re-zones to `now.time_zone()` for display, so identical inputs took two divergent code paths and only one matched GNU `date`. GNU treats a trailing TZ abbreviation as describing the *input* timezone; the output is always re-zoned into the local zone (or UTC under `-u`). For example, under `TZ=UTC`: $ date -d "2024-01-01 EST" # GNU Mon Jan 1 05:00:00 UTC 2024 uutils previously emitted `Mon Jan 1 00:00:00 -05 2024`. Convert the parsed instant to `now.time_zone()` before returning, matching the fallback path and GNU’s behavior. `-u` still works because `now` is already zoned to UTC in that case (date.rs:362), and the final output stage still applies `with_time_zone(TimeZone::UTC)` when `settings.utc` is set. Un-ignores the existing regression test for this issue. Fixes uutils/parse_datetime#281.
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Summary
try_parse_with_abbreviationinsrc/uu/date/src/date.rsreturned aZonedin the input abbreviation timezone (e.g.-05forEST). The genericparse_datetimefallback already re-zones tonow.time_zone()for display, so identical inputs took two divergent paths and only one matched GNUdate.GNU treats a trailing TZ abbreviation as describing the input timezone; the output is always re-zoned into the local zone (or UTC under
-u). UnderTZ=UTC:What changed
The abbreviation-aware path now does the same
with_time_zone(now.time_zone().clone())re-zoning the generic fallback already does.-ustill produces UTC output becausenowis zoned to UTC in that case (date.rs:362), and the final output stage still applieswith_time_zone(TimeZone::UTC)whensettings.utcis set, so the existing-u+ abbreviation tests (test_date_utc_with_d_flag,test_date_tz_abbreviation_fixed_offset_outside_season) are unchanged.Testing
tests/by-util/test_date.rsalready contained an#[ignore]d regression test for this issue; this PR un-ignores it. Fulluu_datetest suite is green locally:Fixes uutils/parse_datetime#281.