Hello there -

Any help or advice on this would be greatly appreciated.

Basically, I am creating timestamp fields that cover the beginning and end of reservations times.

I'm wondering if there is a calculation function that will count the number of time overlaps and then post that information in a different field.

For example, if I had one reservation from 3-5pm and another from 4-6pm, I want Filemaker to record that there is a conflict with the 2nd reservation.

You need a relationship first. See here for an example:

http://www.fmforums.com/forum/showtopic.php?tid/194990/post/289156/#289156