KITFORMA · EDITORIAL GUIDE
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 guidance
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:
Scope: This editorial guide is based on the cited sources and tool behavior. A forum question or a query observed for our site does not establish market search volume, low competition, guaranteed rankings or inadequate answers elsewhere.
This starter guide was prepared by KitForma with AI assistance. It is not presented as a real member question or an independent user review. Check the sources and the result with your own file; report corrections in the discussion.