You can set to send a fax at a specified time. Only monochrome faxes can be sent when the time to send is specified.
You can find the menu on the printer's control panel below.
Fax > Fax Settings
Enable Send Fax Later, and then specify the time of day to send the fax.
To cancel the fax while the printer is waiting for the specified time to arrive, cancel it from Job/Status on the home screen.