Georgia voters begin determining which political party controls the U.S. Senate Monday.

Both of Georgia’s Senate seats are up for grabs as Republican incumbent Sens. David Perdue and Kelly Loeffler try to hold of Democratic challengers Jon Ossoff and Raphael Warnock. Democrats would need to win both seats to flip control of the Senate.

Early voting starts at 8:30 a.m. in Fulton County. Thirty-two voting locations are open and listed on the Fulton County website.

Early voting locations are also open elsewhere in the state, including in Cobb, DeKalb and Gwinnett counties. Early voters may cast their ballot at any location in their county.

In Fulton County, weekday voting hours are 8:30 a.m.-6 p.m. through Dec. 23. Hours are extended to 7 a.m.-7 p.m. from Dec. 28-30.

On Saturdays, Dec. 19 and Dec. 26, voting will be held 8:30 a.m.-6 p.m. On Sundays, Dec. 20 and Dec. 27, voting locations are open noon-6 p.m.

Voting locations include State Farm Arena from Dec. 14-19; and Mercedes-Benz Stadium from Dec. 22-Dec. 30.

Wait time estimates at polling locations will available on the Fulton County website and the Fulton Votes mobile app, an official said.

Polls will be closed Dec. 24-25 and Dec. 31-Jan. 1 in observance of the Christmas and New Year’s holidays.

Election Day is Tuesday, Jan. 5.

Metro early voting locations, dates and hours:

* Cobb County

* DeKalb County

* Fulton County

* Gwinnett County