The time start field is a field in which the time start is entered. Then the appointment title is chosen, let us say, Indiv. Ther. w Med One can see these as I note in my first post by selecting the 5th, tomorrow in the initial screen, the daily layout, then one of the people. This brings up the edit appointment mini screen. If Indiv. Ther. w Med is chosen the field next to it is a related field, the default time from the psych appointments types table. It is in that table, reached from the daily layout via the green text at the bottom. The fudge field is immediately below the related default time field in the previously mentioned edit appointments mini screen. It accepts time in the standard filemaker format, or at least it should. That part of the calculation seems to work. If I add time to that field it works fine. If I subract time it also works. But the calculation seems to ignore the related field. As I mentioned in the post which includes the file, in the original of this file which has about a thousand entries and the full names of the patients, and in that file several of the calculations work, but three do not. I don't know why changing the names of the patients effected the calculation at all.