The League One game was originally due to take place at Glanford Park at the usual 3pm time, but has been brought forward on the advice of Humberside Police.
Tickets for the game will go on sale from Monday July 21, with prices starting at £16 for adults.
Two other games have been moved: the trip to Bristol Rovers will now be played on Friday November 14, and the home match against Huddersfield has been brought forward to Friday April 10.
The Rovers game has been moved due to a clash with a Bristol City home fixture, with the two Bristol clubs unable to play home games at the same time due to policing concerns, while it was United who asked for the visit of Huddersfield to be moved.
It is to give the players an extra day's rest before the trip to Hartlepool the following Monday.
The club have also confirmed that home midweek games will take place at their traditional 7.30pm slot, rather than the 7.45pm time favoured by most other clubs. The one exception is game against Huddersfield.