I assumed that all presents had to be delivered at some point on Dec. 25th, local time. I did not take daylight/darkness into account, since he would have such a short time in any given house that you wouldn't be able to see him anyway.
Joined: Oct 13, 2005
You mean after 2000000000 chimneys Santa will be so black with soot nobody will be able to see him? In that case, 48 hours.