Can I average a column of times (that were determined as a difference from two other columns)? The times are being formatted with a MOD function due to the times could be on two different days.

Now to make it more complicated, I would like to only averge the time difference that corresponds to another column that is represented by a constant.

Ex:
Col A Col B Col C Col D
2 12:14 12:15 0:01
1 23:56 00:02 0.06

I am trying to determine the time difference between Col B and Col C with the result in Col D. Again I am using a MOD due to date change. I then want to only pick out all "1" or "2" in Col A and average the time difference in Col D that corresponds to that.

Do I need to format the cells differently than times?

Please help!