All PM series printers have real time clocks in them. They become functional when a battery is inserted in the printer’s motherboard. You’ll have to remove the cover to access this; the PM43c battery slot looks like this:
The printer’s display will show the date and time if a battery is installed.
Only printers configured with 802.11 WiFi boards can be ordered with a battery installed from the factory. You can order the battery separately, part number 318-051-001 , but they are a standard battery that you can get anywhere:
In the newer firmware you can also configure the printer to contact a time server to synch its clock. Select Wizards, Calibration, Date & Time from the main to enable the time server.
If your printer can’t be connected to the Internet you can sill use the real time clock by manually setting the date and time using the Wizard or the System settings.
NB: When you set the time manually make sure that you use GMT time, not your local time. There’s a bug in the firmware that will change the clock setting according to the time zone and DST settings when the printer’s power is cycled after the clock is set.