Originally Posted by
gengar
It's a good question. I recently had a UA flight with a delay of 4 hours and showed up to check bags ~90mins before the flight departure and had no problems. I'd have been pretty miffed if they'd told me I could only check bags in 5 hours before the rescheduled departure time!
But it won't have been formally rescheduled. It will be delayed which isn't the same thing at all.