The Football Association confirmed on Friday that the FA Cup semi-final between Manchester City and either Manchester United or Chelsea will take place on Sunday, April 14, with a 1600GMT kick-off.
The other semi-final, between Wigan Athletic and Championship side Millwall, will take place the day before.
Both matches will be played at London's Wembley Stadium.
With Chelsea set to travel to Russia to face Rubin Kazan in the Europa League on April 11, the FA had no option but to schedule their potential semi-final for the Sunday.
The FA also confirmed that Millwall and City have been allocated the west end of the stadium and will receive 31,514 tickets.
Wigan and the other semi-finalists will get 31,863 tickets.