KITFORMA · EDITORIAL ANSWER
How do I represent the repeated hour when daylight saving time ends?
KitForma editorial guide. A local wall-clock time may correspond to two instants during a backward clock change. A timezone name alone does not always identify which occurrence was intended.
Step-by-step answer
A local wall-clock time may correspond to two instants during a backward clock change. A timezone name alone does not always identify which occurrence was intended.
Use
zoneinfo.ZoneInfo and an explicit fold choice when resolving an ambiguous local time. Prefer collecting an offset or UTC instant from the source rather than guessing. Test conversion to UTC and back for both occurrences in the actual zone and date. Nonexistent times during the spring transition require a separate validation policy; fold is not a universal input validator. Keep timezone data available in the deployment environment, especially on systems without an IANA database.Sources and verification
Sources checked:
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