Thomas Earnshaw watches use the quick date-change system, which starts to change the date at about 11.45 pm and comes to its end at 00.15 am. The date of the ending day can be seen in full until 11.50 pm. Between a period of 10 minutes before and after midnight, the calendar jumps and thus the next day date appears on the watch.

Avoid changing the date manually between 10 pm and 2 am, since this is the period during which the automatic date-change is in operation.