That's something that's often fascinated me and I've never looked into.
Does the transmission just stop and then restart X minutes Z seconds behind schedule, and continue? If so, where does the deficit get made-up?
If it's possible to do such a thing for an entire day it might, just, be possible but I still find it infinately unlikely.
RIP Fardin Qayyumi (AKA "cricket player"; "Bob"), 1/11/1990-15/4/2006