The following illustration and its corresponding table describe the physical features of the Vodavi 24-Button Digital Display Telephone.
Purchase Vodavi STS phones at http://www.telephonesystemsdirect.com/ccp0-prodshow/Vodavi-STSe-24-Button-Phone.html.

1. (DISPLAY) Displays information about telephone status, dialing directories, and text message information.
2. (MESSAGE INDICATOR) Programmable indication for Ring Line, Voice Mail, Message Wait, or handset operation.
3. (FLEXIBLE BUTTON Keys) Used to access [...]

These are the instructions on changing the time and date on a Vodavi STS phone system. Unless your phone system was purchased from www.telephonesystemsdirect.com you must use Vodavi extensionon 100 for this programming change.
Do not lift handset or press speaker.
Dial **3226 on your Vodavi STS 24 button digital key telephone.
Press the FLASH key and dial 11
Enter [...]

In most cases you need to log in from the operator phone. On Plug & Play phone systems from Telephone Systems Direct you can log in from any phone.
At the phone press  * * 3226
Press Hold.
The phone should beep 2 times and wait for your next command.