The split admission doubleheader will be played at noon and 5 p.m. ET. Both games will be televised on NESN.
Fans who had tickets to the originally scheduled 1 p.m. game on Saturday must use them for the noon game. Tickets for the Sunday 1:35 p.m. game will be honored at Saturday's nightcap.
The Red Sox will keep their pitching in order, going with Jon Lester in Saturday's opener and Erik Bedard for Game 2.
The only other scenario the Red Sox had available to them was to play a day-night doubleheader on Friday, with Game 1 at 3 p.m. and Game 2 at 8.
But player representative Daniel Bard said the Red Sox voted that scenario down.
After an 8:05 p.m. ET game in Texas on Thursday, the Sox will spend the wee hours of Friday morning traveling home.
"We can't do that. You can't ask guys to play 18 innings -- we're going to get in at probably 5 a.m.," Bard said. "That was quickly shot down. We'd rather play the game at the end of the season than do that."
However, Bard said that Major League Baseball was emphatic that the clubs needed to do anything possible to play a doubleheader on Saturday instead of playing a game the day after the regular season ends.
The postseason is scheduled to start on Sept. 30, just two days after the regular season ends.
As it is, if weather complicates one or both of Saturday's games, they will probably have to be made up after the season ends. But everyone hopes the doubleheader can go off as scheduled.
"That's the day that made the most sense for everybody," Bard said. "Obviously travel is going to be pretty tough leading up to it. We were trying to get creative and find another way to do it. That's just the way it worked out."
"The current forecast calls for a consistent period of moderate to heavy rain and strong winds beginning late in the day on Saturday and continuing through Sunday evening as Hurricane Irene moves up the east coast and into New England," the team said in a press release.
"With a forecast that calls for potentially heavy rains and high winds on Sunday, we felt it was necessary and prudent to move the Sunday game to Saturday, also," said Red Sox president/CEO Larry Lucchino. "This will not only give us the best opportunity to play the scheduled games, but also help to insure that traveling conditions are safer for our fans. We apologize for the inconvenience these changes will cause our fans this weekend, both those coming to the ballpark and those tuning in to the game on radio or television.
"On behalf of [principal owner] John [Henry], [chairman] Tom [Werner] and our entire front office, I also want to express gratitude for the flexibility that our players and our fans have shown this season as, together, we've dealt with an extraordinary number of weather-related scheduling issues."
It was a decision that included several parties, including Major League Baseball, the MLB Players Association, the Red Sox players, and the Oakland Athletics.
Bard said the players had the option of playing a straight doubleheader rather than a split gate.
"[It] wasn't even worth taking the money out of our front offices' pocket," said Bard. "We just decided to do [the split doubleheader]."