time format

When specifying time for schedule (edit pop up > scheduling) there’s no indication as to how to set the time. I want to schedule from 8 O’clock in the morning to five in the evening.

So – is this:
8 O’clock – 5 O’clock
08:00 to – 17:00
8am – 5pm
Etc, etc

Bit of flaw in the UI here – advice please

Using FF 141.0.2 in Mac OS15.6