"This would be easy enough to understand were it not for the fact that the day finishes at different points depending on where you are in the world. To clarify, businesses set the deadline as 'End of Day, Anywhere on Earth', meaning when the clock turns to 00:00 on Howland and Baker."
Maybe I'm dense, but I don't see how "End of Day, Anywhere on Earth" means when the clock turns to 00:00 on Howland and Baker. Howland and Baker are in a time zone just like everywhere else.