This is due to the Yorkshire derby being selected for live coverage by Sky Sports. The game at the Coral Windows Stadium was originally due to take place the day before - Saturday 19 September 2015 (kick off 3:00pm).
This is the second season on the trot that Sheffield United's visit to BD8 has been shown live on Sky Sports.
The Sky Sports cameras were also at Valley Parade last October to cover City's encounter with the Blades at Valley Parade as well.
At present, the Sheffield United home fixture is the only one to have been altered from City's original fixture list handed to them back in June.