- Add timestampToLocalDatetime() to convert Unix timestamp to local datetime
- Add localDatetimeToTimestamp() with validation for incomplete input
- Fix issue where typing hours/minutes would jump to previous day
- Validate datetime format completeness before conversion
- Use local timezone instead of UTC for datetime-local input
This resolves the issue where users couldn't fine-tune time selection
and the input would jump unexpectedly when editing hours or minutes.
YoVinchen
4a1ee98784