5887

The tourbillon system was made to compensate the Earth’s gravitational force by mounting the escapement in a revolving cage. It gives the watch a better accuracy. This complication is known as one of the most difficult to make.

The equation of time is the difference between true solar time and mean time. True solar time varies from day to day because of the Earth's elliptical orbit. Mean time, given by watches, ignores these variations and for every day of the year mathematically divides time into equal hours.

The perpetual calendar complication displays the day, date and month, but it requires less adjustment than an annual calendar. This complication knows the number of days in each month but it also knows the year so that it will automatically adjust for leap year. The next time a perpetual calendar will have to be adjusted is in the year 2100.

The date is a small window on the dial which indicates the day of the month (between 1 and 31).