SEP 12.1 Skipping LiveUpdate Option

Looking for more detail on the skipping LiveUpdate when defs are more than two days old.

Is this a calendar date check, or a more detailed determination.

If my client updated definitions a 4:45 PM on 5/1, are definitions two days old at 00:00 5/3?

 

Getting spike on external LU connections at the perimeter, and laptops are powered off Friday and starting up Monday and meeting both check to launch LU while trying to complete first heartbeat to SEPM.