Shifting of the date is between 10:00 p.m. and 2:00 a.m. Please do not try to adjust the date disc during this time.
How to set the date disc:
On the back side of the clock you can see the date disc. Turn the disc clockwise or counterclockwise until the correct date is seen in the opening of the dial.
After a month with less than 31 days, a manual adjustment is necessary.
If you set the date, be sure that it is not done between 10:00 p.m. and 2:00 a.m.