This is true for my husband also. He does occasionally go into the office early in the morning for an hour or two before a trip to count one less vacation day, but he routinely works a 60+ hour week, not counting all the work he does on weekends etc., so his employer definitely gets the better “deal” in this situation, even counting the few times he’s worked short days.
PS. Long, long time lurker, occasional poster when I have actual knowledge on a subject to help, but had to change user name.