Average Time Across Midnight

I'm looking for a better way to allow my pivot table to display the correct average time when the range of values contain times both before and after midnight.

Incorrect Average

11:56 PM
12:17 AM
12:05 AM
8:06 AM Average

Correct Average
11:56 PM
12:17 AM
12:05 AM
12:06 AM Average

Currently, my solution has been to locate all of the post-midnight times and add 24:00 hours to them (12:17 AM >>> 24:17; 1:37 AM >>> 25:37). This works, but my source data is dynamic so having to go in and change it before updating the tables seems prone to problems.

Any ideas on how to workaround this?