For example, on your average calendar watch, the watch doesn’t distinguish between months with 28, 29 and 30 days, it simply turns for the full 31 days. At the end of each month, the owner must manually change the date to account for the difference, if need be.
A watch with a perpetual calendar function, however, can account for this difference and advances the date automatically. It even accounts for leap years, so that the appropriate amount of days are ticked over in February.
Setting the perpetual calendar on the Cartier Chronoflex is somewhat tricky, but once it’s set, one needn’t worry about setting the date for as long as the battery lasts. The only thing that need be done is to add or subtract an hour each year to account for daylight savings.
Setting the chronoflex is a six step process (seven, if you also need to reset the chronograph hands). The process may sound daunting, but once it’s set, you’ll get years of enjoyment from your piece, knowing that it’s always right on time. We recommend you let your watchmaker do it for you though (and give him this guide, because he’ll be hard pressed to find anything online about it) as it involves opening up the caseback.
Though the Cartier Chronoflex doesn’t display what month or year it is, the internal memory needs to know these things in order to display the correct date.
Step #1 - entering initialisation mode:
- Pull the crown into position 2. (i.e. all the way out.)
- Adjust the hour and minute hand so that they display a full hour. (i.e. the minute hand at 12, the hour hand on 1, 2, 3 etc.)
- Press the bottom chronograph pusher 3 times followed by the top pusher 3 times.
Step #2 - Initialization of the Year:
You needn’t know the exact year for this step, but you need to know whether the current year is a leap year or what year it is in between one. (For example, 2016 is a leap year, 2017 the one after, 2020 being the next leap year.) The dial is divided into four segments divided by the numerals 12, 3, 6 and 9, with 12 being the leap year and 3 the year after, and so on.
- Press the bottom pusher, which will move the seconds hand ¼ of a turn.
- Keep pressing until it’s positioned on the appropriate numeral.
- Press the top pusher to commit the year to memory.
Step #3 - Initialisation of the Month:
The 12 hour numerals represent the 12 months of the year.
- Press the bottom pusher, which will move the seconds hand 1/12 of a turn. Keep pressing until it’s positioned on the appropriate numeral.
- Press the top pusher to commit the month to memory.
The watch should now be in the date setting phase.
Step #4 - Initialisation of the Date:
The actual date subdial is not used in this step, nor will it change at this point. This step simply commits the correct date to the internal memory - the actual date displayed on the dial is changed at a later step. The first 31 minutes on the dial represent the days of the month. If you move the seconds hand past the 31st minute it’ll automatically return to the 1st minute. Each press of the bottom pusher will move the seconds hand along one minute.
- Press the bottom pusher until the seconds hand is on the correct date.
- Press the top pusher to commit the date to memory.
Step #5 - Initialisation of the Hour:
In this step, the watch needs to know what hour it is on the date you set in the previous step. The first 23 minutes on the dial (12 o'clock being the 0’th hour) represent the 24 hours in a day.
- Press the bottom pusher until it’s on the correct minute.
- Press the top pusher to commit the hour to memory.
Step #6 - Correcting the Calendar:
If the date displayed on the dial is already correct, you can skip this step.
- Open up the case back of the watch.
- Turn the small correction screw until the date displayed is correct. Each 90 degree turn advances the date hand one day.
- Replace the case back.
Step #7 - Correcting Alignment of Chronograph Hands:
If the chronograph hands are already aligned ( all at 12 o’clock), you can skip this step.
- Pull the crown into the first position. (i.e. not all the way out.)
- Press and hold the bottom pusher
- While holding the bottom pusher, press the top pusher 3 times in succession.
- Press the bottom pusher until the chronograph hand is at 12 o’clock.
- Press the top pusher once to exit chronograph correction mode and enter the correction mode for the hour and minute counters.
- Press the bottom pusher to advance the counter hands until they’re both at 12 o’clock. (Maintaining pressure on the bottom pusher will cause the hands to advance rapidly.)
- Press the top pusher to exit the chronograph setting mode.
- Push the crown back in.