SUMMARY
On Slackware GNU/Linux 14.n,14-current, (earlier) FreeBSD Unix 12.n,13-CURRENT, night color won't let you use night shift.  It says like: error: morning is before day.  Some people live/work night shift and others have disabilities making them live night shift, but it's not up to you to force them onto day shift!

STEPS TO REPRODUCE
1. Put a night color start time it still transitions (like 255mins) after midnight (sometimes required, even if you want to start fade-out at 7:15PM, because of another bug that night color uses time offset seven or eight hours later, not system time.)
2. Put night color end time later that 24hr day.
3. Get error that morning is before day.

OBSERVED RESULT

Can't use night shift (even if you're only doing it because night color time calculation is messed up) so can't even use night color, exacerbating problems.

EXPECTED RESULT

Let people on night shift live normal lives.

SOFTWARE/OS VERSIONS
Unix/KDE Plasma FreeBSD Unix 12.n,13-CURRENT
Linux/KDE Plasma: Slackware GNU/Linux 14.n,14-current
(available in About System)
KDE Plasma Version: 5.19.4
KDE Frameworks Version: 5.72.0
Qt Version: 5.15.1

ADDITIONAL INFORMATION