The day program was taken out on newer models of Partner systems where it uses the date to figure out the day of the week.
Changing the date on a Partner system is done on either ext 10 or 11.
At one of those ext's press the feature key and "00"
next press the left hand intercom twice
the display should say system
programmingenter in "#101"
the display should say system date and the current data in mm,dd,yy format
enter the new date month, day then year
press feature "00" to logout
If you have an older model Partner system,you'll also have to enter in the day of the week in programming
Press the feature key and "00"
next press the left hand intercom twice
the display should say system
programmingenter in "#102"
the display should say system day and the current programmed info
enter the new day, 1= sun, 2= mon, etc.
press feature "00" to logout