The first game on Tuesday will be at 1 p.m. and the second game at 7 p.m.
The Nationals will make up their postponed game with a doubleheader Thursday, giving them twin bills on consecutive days.
Nats release 2015 schedule
The Nationals were hoping to avoid the hot August weather by moving an early afternoon game to 5:05 p.m.
The afternoon game was picked up by ESPN and moved to 8 p.m.
With the second half soon to begin, oddsmakers have picked the Nationals among the NL favorites.
Rain postponed Tuesday's Nationals-Orioles game. The teams will make it up Aug. 4.
Only 13 hours after Tuesday's game ended, the weary Nationals suit up again for another game.
The make-up game will be at 1:05 p.m. and the regularly-scheduled game at 7:05 p.m.
The two teams will make up Tuesday's rained out game in the final series of the regular season from Sept. 26-28.