Watches featuring a GMT complication (which stands for Greenwich Mean Time) can display a second time zone thanks to an additional hand. They are much appreciated by travelers and airline pilots.
The power reserve indicator tells you the time the watch will continue to function. It can either be seen on hand winding or automatic watches.
The 24H indicator is often associated with watches displaying several time zones.
The date is a small window on the dial which indicates the day of the month (between 1 and 31).