Every once in awhile I will have maintenance windows that need to start at Midnight. When announcements are made, there’s always going to be one person out there that gets the day wrong. If I say the system will be unavailable Wednesday at Midnight, I will be asked if I mean Tuesday night leading into Wednesday morning, or Wednesday night leading into Thursday morning.
Technically, Midnight is the beginning of a new day. If you’re used to military time, it’s easier to understand, since you’re starting over at 0000. But most people have always used Midnight in the context of a late evening, as in, I’m going to stay up until Midnight; so it’s pretty common to accidentally associate it with the previous day.
To overcome confusion, we announce all Midnight maintenance windows as having a start time of 12:01 AM. It’s close enough to Midnight, and for some reason, everybody seems to understand it. Sure, Midnight is ambiguous, but 12:01 on a Wednesday is clearly early understood as Wednesday morning. I’m not going to complain about a one minute compromise if it means avoiding ten minutes of writing emails to clarify the schedule.