[toruviel]

it persists even after. because this bug manifests in a following scenario (this is my hypothesis):
1. you put date without hour (in any format)
2. you press tab
3. OF adds default time (being 00:00 or 17:00)
BUT DUE to fact that my system preferences use time without colon (0000 or 1700) problem arises
4. new date and time (complete) does not contain colon in time, and is parsed once again by OF with error, because datetime string parsing in OF has bug when there is no colon in it

Thats my hypothesis.

You can check it yourself just by setting in system preferences time settings as I showed in my screenshot. Bear in mind that OF restart is required.