Election Day is tomorrow but local election officials in Iowa are allowed to start counting absentee ballots today.

Chad Olsen, chief of staff to the Iowa Secretary of State, says more than a half-million Iowans voted early already and it’s getting much harder for elections officials to finish counting votes before the deadline.

Olsen says, “A few years ago, there was a county auditor who wasn’t able to get them all completed by 10 P.M. on election night, so now county auditors can begin counting on Monday November 5th.”

About one-third of Iowans voted early in the last presidential election and thousand more have done so this time. All mail-in ballots must be postmarked by today and arrive by noon on November 13th in order to be counted in official vote tallies.

Those ballots could be a deciding factor in extremely tight races. Olsen says it’s important to start counting the absentee ballots early because so many Iowans have already voted early, either in person or by mail.

“County auditors will be looking at counting four out of every ten ballots, 40% of the votes may be cast before Election Day, Olsen says. “The only requirement is that they must be done by 10 P.M. on Tuesday.”

The Iowa Secretary of State’s office says nearly 614,000 Iowans have voted already. That surpasses the early voting record set in Iowa in 2008 by about 69,000 votes. In Iowa, 43-percent of the early votes came from Democrats and 32-percent came from registered Republicans. The rest were from Independents.

Nationwide, more than 20-million people have voted early.