Dropdown of every 15 minutes in a day

How can I get a dropdown with every 15 minutes of the day? I tried valid if minute() mod 15=0 in a time and enum time column and all I got was a blank dropdown.

That’s going to be one massive dropdown list! I started to go down that path at one point but eventually decided against it.

I think it makes for a better UI to just let the user type any time value they want, then validate the entry only if an even 15 minute interval is entered. Here’s what I ended up doing:

Another option would be to create separate columns for [Hour] & [Minute], with dropdowns of 1-24 and 0,15,30,45. Then you can build the time value with TIME([Hour]&":"&[Minute]).

Mostly I just wanted to avoid the current way appsheet lets you select times. Having to enter in time values in a form was not the most user friendly so I guess I just need to set the defaults times to be the start and end of day. I’m setting up a black out between X day from Y time to R day at S time for interviews that are every 15 minutes.