The match was originally scheduled for New Year's Day, but the Vanarama National League North issued guidance when the fixtures were released that the game could be reverted to the Saturday pending agreement from both teams.
Both Scunthorpe and Farsley immediately agreed for the switch to take place, with United now visiting the Citadel 48 hours earlier than planned.
The match now takes place four days after the fixture at Glanford Park on Boxing Day.
