Montgomery County Agricultural Center 501 Perry Parkway, Gaithersburg, MD 20877 Phone: (301) 926-3100 HOURS OF OPERATION Fair Hours Carnival Hours Friday, Aug. 10, 2018 3 pm – 12 Midnight* (Gates close at 11:00pm for entry) Friday, August 10, 2018 3 pm – 12 Midnight (Gates close at 11:00pm for entry) Saturday, Aug. 11 – Saturday, Aug. […]