This link shows poll closing times for each state:
http://www.270towin.com/closing.php NB: this shows what states might be called at any given time, and NOT when one might be able to vote. For example, in Florida, polls close at 7PM, however the Florida panhandle is in the central time zone, so in that part of the state, polls will close at 8PM eastern, even though most of the state will have been finished voting. The networks will not call Florida until 8PM eastern.
As for calling the entire election, the networks will do that as soon as they think someone has reached 270, irrespective of any states that may still be voting.
"It does me no injury for my neighbour to say there are 20 gods or no god. It neither picks my pocket, nor breaks my leg."
-- Thomas Jefferson