I think the true time is visible in Debug Mode.
This should work:
To get into debug mode go to SETTING 7 "PARAMETER LOCK" and set to OFF.
Go to ALARM page and type DEBUG and press "write" button.
You are now in DEBUG mode.
Now go to the Diagnostics screen and page up or down and you should see some times displayed.
To exit debug mode, type DEBUG once more in ALARM page.