Fix edge case for disambiguating ZonedDateTimes on DSTs skipping midnight
#156
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nekevss
reviewed
Jan 13, 2025
| fn dst_skipped_cross_midnight() { | ||
| let provider = &FsTzdbProvider::default(); | ||
| let midnight_disambiguated = ZonedDateTime::from_str_with_provider( | ||
| "1919-03-31T00[America/Toronto]", |
| @@ -557,14 +558,14 @@ impl TzProvider for FsTzdbProvider { | |||
| LocalTimeRecordResult::Empty => Vec::default(), | |||
| LocalTimeRecordResult::Single(r) => { | |||
| let epoch_ns = | |||
| EpochNanoseconds::try_from(epoch_nanos.0 + seconds_to_nanoseconds(r.offset))?; | |||
| EpochNanoseconds::try_from(epoch_nanos.0 - seconds_to_nanoseconds(r.offset))?; | |||
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Huh, is this correct? I think the tests below due assert that the time zones are not inverted like in PosixTzString, so I'm pretty sure the sign needs to be minus (I could definitely be off here). Ex: EST is -04:00, to move the local back to UTC you local - -04:00.
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Yes. The input is a local time, and the output is an UT. Hence, since local = UT + offset, then local - offset = UT
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OH wait, I had put plus oh god 🤣
nekevss
approved these changes
Jan 13, 2025
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Fixes part of the test intl402/Temporal/ZonedDateTime/from/dst-skipped-cross-midnight.js. This doesn't fix correctly resolving the start of the day for days that don't start at 00:00, since that'll require more advanced logic.