(This question is silly, but fitting for the end of the month.)
When is the latest that a plane owner can legally fly a plane which is due for annual at the end of the month? Is it 23h59m UTC on the last day of the month, or is it time-zone dependent?
If it is 23h59m UTC, then have there been enforcement actions against people for flying out of annual, and yet still on the last calendar day of the month?
If it is time-zone dependent, is the originating or the destination time zone the relevant one? If I took off in EST at 11PM and landed 90 minutes later in CST, having crossed into the CST timezone before 11:59PM, would that be a legal flight? And what about the converse, where the flight starts in a western timezone but finishes after midnight in an eastern time zone?