Panasonic KX-T123211D
Be sure the handset is in the cradle and the SP-PHONE button is off.
Set the MEMORY switch of the proprietary telephone to “PROGRAM”.
0: Sunday
1: Monday
2: Tuesday
3: Wednesday
4: Thursday
5: Friday
6: Saturday
0: AM
1: PM
After setting, return the MEMORY switch to the “SET” position.