Watches with complications such as Calendar, Chronograph and GMT time zone give an extended information by special indicators.
Apertures are rectangular cuts in a dial for indication of the date.
Subdials are used with a Chronograph. There can be up to four of them on a main dial.
Numerical or graphic indicators like in Power Reserve Indicator let the owner know how long will the watch work without till next winding up.
Additional scale is used for functions like GMT time zone or Tachymeter.
To show the time following markings are used:
Though many models have blank dials.
In some rare models the hands are placed on different parts of the dial, and for each hand there is own marking for seconds, minutes and hours.
Diverse complications are displayed by special markings: