In that example project Day light savings has been enabled, such that when 3'o clock is struck, it changes to 4'o clock.
You can disable the DST in the RTC Component settings.
- Madhu Sudhan
Sean, of course does the RTC run from 02:59:59 to 03:00:00 I cannot see what you did wrong.
RTC will run as long as power applied. Precision will depend on crystal use.