Date window

The date window is the opening in the dial that shows the date disc beneath.

The font, colour, and alignment of the date numerals are specific to many references and production periods, and they're a detail often got wrong on replacement parts and fakes.

Advance the date through several days at intake to check that it changes cleanly and that each numeral sits centred in the window.

If the date doesn't change at all, or changes at midday, check the setting before assuming a fault, since the time may simply be set twelve hours out. A date that sticks between numerals, though, usually points to a mechanical issue that needs a watchmaker.