How can I limit a time field to accept only 15 min increments? ie 10:00 AM, 10:15 AM, 10:30AM, etc.

Several ways provide a time popup one of hour / one for minute the minute field could be a set using 0 / 15 / 30 / 45

You could also round the value entered to the nearest increment.

or a validation calc

If (

Minute ( time ) = 0 or

Minute ( time ) = 15 or

Minute ( time ) = 30 or

Minute ( time ) = 45 ; True ; False )

... but the time field could contain 59 seconds ( 10:15:59 ) and pass the validation.

It's better:

not Mod ( Self ; 60*15 )

P.S. Stephen, could you read my post: "Is it broken ?" :

Where do I put that? Do I type it into a validation calculation?

Yes.

This works good since my format doesn't have any seconds. Is there a way though to have it automatically change instead of just giving a validation warning?

So both work fine. Is there a way to have it automatically change when they type it in?

Yes, there is.

You'll need to eliminate the calculation into the validation option fot that field and, instead, put a calculation into the auto-enter option for that same field.

A calculation that works may be:

Time (

Hour ( Self ) ;

Case(

Minute ( Self ) < 8 ; 0 ;

Minute ( Self ) < 23 ; 15 ;

Minute ( Self ) < 38 ; 30 ;

Minute ( Self ) < 53 ; 45 ;

60

) ;

0

)

P.S. I remember that "comment" made a better calculation

How about =

Round ( Self / 900 ; 0 ) * 900

That was it !! ( ... and it is the best )

I forgot that one.

BTW, searching a better one than previous mine, I reached:

Time ( Hour ( Self ) ; Div ( Minute ( Self ) + 7 ; 15 ) * 15 ; 0 )

Comment to the rescue again!

Do I use this as a validation or a calculation?

It's a calculation - it rounds time to the nearest quarter-hour.