Hey Pim,
Thanks for contacting us!
The time format for events uses the same format that is set globally for your entire WordPress site. From the main dashboard, head over to Settings > General. There is a section towards the bottom of the screen called “Time Format” that gives you a variety of options to choose from, including the military time format you are looking for.
I hope this helps! 🙂
Let me know if you need anything else and have a great weekend!
Regards,
Patricia