24hr clock instead of AM & PM

When adding the time to an event I have to enter the time in an AM / PM format.
To me (and my client) this is confusing since this is not the way we are used to notate time. Here we use the 24 hours clock. So I don’t want to enter 10.00 AM – 1.00 PM, but I want that to be 10.00 – 13.00

On the calendar itself it is shown correctly, so that’s good, but I would really prefer if I could choose a 24 hours setting in the input in the editor as well.

Is this possible? And if so, how would I achieve that?

Thanks in advance!!