The Reds have benefited from the rearranged fixtures and gained some solace after their shock FA Cup third round defeat by Leeds.
The first leg at City has been shifted to the date originally set for the second match at Old Trafford.
It now means the opener at the Blues' HQ will take place on Tuesday, January 19 with the return at United's ground on Wednesday, January 27.
And that means United will have a free weekend before the second leg in the wake of their ignominious FA Cup exit.
Roberto Mancini's Blues, meanwhile, will play their fourth round tie against Scunthorpe United on the Sunday, January 24.
It will leave City just 72 hours to prepare for the visit to Old Trafford, while United will have had the comparative luxury of putting their feet up for eight days .
The downside for the Reds means it has lopped a day off their preparations for the Premier League visit to Arsenal the following Sunday.
United had been due to play Hull City at Old Trafford on the Tuesday but that game will now be rearranged.
When the semi dust-up does finally arrive nobody will be more excited than Wes Brown (pictured).
"I love matches like this. It is brilliant for the fans and I am really looking forward to it," said the Longsight-born defender.
"It is better to have two games against City.
"Hopefully we can give them two good football lessons. Whether that will happen I don't know. They are a good team.
"It is a good thing in a semi-final that we get an extra game to sort it out. Both teams have a chance at home.
" You want to do a good job in the first leg but you always have that opportunity in the second, so it makes it interesting.
"If we did lose the first one, Old Trafford would still be buzzing for the second. The crowd would get right behind us. We are confident."
Source: Manchester Evening News