(solved earlier) "24" as the third option to "AM" and "PM"

(Delete please. I should have looked into the settings first). An existing task's time is shown in 24 hour format (according to regional settings, I suppose), which is good, but it does not allow to enter the time in 24 format, letting to choose only from AM and PM. When one is used to enter time from a numpad in usual format, there is a risk not to spot the mistake (like 1:30 AM instead of 13:00 24h). Is it possible to add the option "24"?