Have a “building rental form” where I want the user to pick their rental time at 15 minute increments only,

I would like to use the Time field input, though have it limited to only :00 :15 :30 or :45. Is this possible? I am trying to calculate two time fields, like start time and end time, and then calculate the difference to create a “total time”. Am I barking up the wrong tree here? Should I just use numeric drop-downs and then calculate the difference of those? Thank you.

Thanks for the response Dario. My brain can’t figure from looking at the snippet how this would limit time increments to 15 minutes. I understand that the Gravity Wiz can calculate the difference in times though. However, I may have to do this numerically as I also need the total time to be multiplied by a rate for a “rental total”.