How long does Santa have to deliver his gifts?

On Christmas Eve, Santa Claus has 36 hours to deliver his gifts. He starts as the sun goes down on the 24th just west of the International date line and he heads west, going with the night. Twenty-four hours later, the sun is just going down on the 24th east of the date line. But there is another 12 hours before the night is over here, making 36 hours.

But Santa delivers presents on other days in some parts of the world: 6-December in many places.

He has only 31 hours.

Santa cannot arrive until the children are asleep. Some people suggest that he start to distribute presents in each time zone at perhaps 9 PM local time, finish within an hour, and then move one time zone to the west. But that is a higher level of performance than is really needed. He could take longer in each time zone, as long as the entire job was finished comfortably before children woke up in the last zone. Assuming that the children sleep for 7 hours, this gives him 31 hours (or a total of 1860 minutes, or 111,600 seconds) to finish all deliveries.

http://www.religioustolerance.org/santa2.htm

Santa actually has 45 hours, because he lives at the north pole, he must start and end at that location. So if he starts at dusk, just west of the IDL and travels west (with the darkness). It would take 23 hours to return to the eastern edge of the IDL, and arrive at the same time that he left (because there are 24 time zones). And since it remains dark in the north for approx 22 hours per day -> 23 + 22 = 45