Concur. Got bit by this one a couple of years ago. Bid month start Monday morning, 7am show for a European deadhead to somewhere. Deviated and took the train later in the day. When it came expense report time, I couldn't understand why the $$ were in last month's bank. Monday 7am Europe = Monday 1am Melvis and local base day starts/ends at 0130Local. The expense report folks pointed out my time zone "error".

If you are deviating, you gotta know your show time in your local base date and time. So, be very careful with $$ associated with Bid Month Monday deadheads unless you are going as scheduled.