Providing a calendar function on a wristwatch has been a desire since the early days. Most watches leave it at displaying the current date.
It can be achieved through a date window with a rotating disc underneath or a date hand that moves forward at midnight. More sophisticated mechanisms display a large date typically achieved with two separate rotating discs.
However, adding more information like day of week, month or in its most complicated form, leap year within a Perpetual Calendar mechanism is often reserved to high complication time pieces.
But what if I want to know what day of the week the 20th this month will be or want to know what date is the last Sunday of the month? Well in most cases you need to go back to your desk or wall calendar, unless…
you are a lucky owner of the Girard-Perregaux Gyrodate!
A clever yet manually operated calendar function that allows you to check a full month at one look aligning date and weekday through a rotating bezel. In fact, you could easily as well adjust the slider to check previous and coming months as well.
The Girard-Perregaux Gyrodate is from the late 1960s, Model Reference is 9080 and within the same reference it was available with two different calibre versions, either as a HF Chronometer or as a normal non high-beat Gyromatic.
And the steel case as well had an option of white or black dial. As it happens my black is the non-HF while my white dial is the Chronometer HF version, but it could have been also the other way around, this is not fixed to the dial colour.
A gold-plated version was also available typically then having a gold-coloured dial.
The case is a good 36mm which is generous for a 1960s vintage watch and with the prominent rotating bezel, the watch feels larger on the wrist.
There are other small differences which become obvious when having a closer look. For example, on the black dial, the interim indexes between 3,6,9,12 are just painted on the dial, while on the white dial version all indexes are applied. Furthermore, the black dial has some small tritium lume dots at the indexes while the white one doesn’t.
And if you think about, that totally makes sense. I probably would have done it exactly the same way as it just provides the most coherent design. GP always had that level of attention to detail, which we can still find today.
Looking from the back, you can see another interesting feature. The case is a front loader. In fact, case and bezel are completely separate from the plexi/dial/movement and case back. You could push the entire watch out of the case for service. In order to get to the movement however, you will need to remove the plexi. That design was typically used to achieve some level of water resistance.
Black or White? Yin or Yang? No, impossible to decide on a favourite. I think they belong together like twins and I’m very happy to have the couple. A great example of a vintage GP from the 1960s with a very interesting calendar function and a great look on the wrist.
Gyromatic Caliber 42 HF and non-HF