Calendar watches has been popular for a very long time! One of the most popular model is probably the Triple Date with Moon Phases – Time, Day, Date, Month and Moon Phase.
It’s not an annual calendar, it’s not a perpetual calendar, yet it gives you all the features you need in a glance at your wrist!
From the mid 1940’s this combination of complications became very popular in wrist watches. Many brands had one or several models in their collection!
Contenders in this class were many – Angelus, Breitling, Cartier, Cortebert, Juvena, Omega, Pierce, Rolex, Vacheron-Constantin, Vulcain… Just to mention a few, there were many more.

And of course – Jaeger-LeCoultre had and still have the Triple Date with Moon Phases in their collection – the Master Calendar!
One of the most famous versions would be the round cased reference 2722 with Teardrop lugs worn by Pablo Picasso among others:

Back in the 1940’s and 1950’s, far from all brands had their own in-house Calibre, I know for sure that Vacheron-Constantin and Cartier used Jaeger-LeCoultre Calibers in several of their calendar watches – but I suspect there were more brands that used Jaeger-LeCoultre calendar movements as well.
Yes, this is another example of “the watchmakers watchmaker“. Different brands acquired Jaeger-LeCoultre movements and decorated as their own.
In early days Cartier watches used to have “European Watch and Clock Co Inc” signed movements which several were based on Jaeger-LeCoultre Calibers.
I encountered many collectors unaware of this, but long before the in-house frenzy we see today – that all brands wants to be true manufactures – many brands chose to use movements from other manufactures instead of develop their own.
This is a rather well-known fact among Chronograph collectors where it is common to see Lemania, Valjoux or Universal movements inside a watch, regardless of the name on the dial – but fact is that this applied to all kind of movements back then!
Like calendar movements, here is one example, movement specifications – Jaeger-LeCoultre Calibre 494 vs Vacheron-Constantin Calibre 495:

Since the mid 1940’s, Jaeger-LeCoultre had many different versions of the Triple Date with Moon Phases and the last one before the 2020 release was the Master Calendar – 176.2.12.S / Q1552520:

The new Master Calendar 2020, reference 4148420:
To me, this is a more elegant version that the previous. The proportions are more to my likings – even if the case is one millimeter larger than before (40 mm vs. 39 mm), the thinner bezel and more slender lugs makes the look and feel of this new creation fresh yet “timeless” and elegant!

Some may argue that the complications are very centralized on the dial but I think it is OK, seen far worse examples of that. On the contrary, I think that here all complications get the space they need to be fully appreciated.
The biggest news to this model is the “Quantième à date sautante” – the pointer date hand makes a big jump between the 15th and 16th each month to avoid the hand to obscure the Moon Phase!
This complication Jaeger-LeCoultre had for years, but reserved for Tourbillon models. To see this jump in a “simpler” watch as the Master Calendar is a real treat!
It may look like a small thing, but to avoid the date hand tangling with the seconds hand and the Moon Phase for a week each month – is a huge improvement in my opinion.
One thing, I as a Jaeger-LeCoultre aficionado, really appreciate is that even if the calendar models have changed over the years, it is easy to see that it is a Jaeger-LeCoultre – the DNA is still there.
This becomes very evident while looking at the guide how to set the time, date, month and Moon Phases – here is the guide for the 2922 from 1952:

Look at the layout, look at the location of the correctors for setting the Date, Month and Moon Phases.
Then look at the 2020 versions guide – the same DNA still there:

Compared with the 2922 this new version also have the advantage of automatic movement, even if you don’t use the watch each day, you can put it on a winder for the watch to keep the calendar going.
Inside is the Calibre 866AA which you are able to admire through the open case back – nicely finished with Geneva bars and “crowned” with a pink gold rotor.

This watch comes on the new calf leather strap which has quick release springs which Jaeger-LeCoultre introduced last year – a great improvement compared to the padded alligator straps that used to be on the Master series.
Of course its a matter of taste, but regardless, I find the quality of these straps much higher than previously.
On the wrist, this Master Calendar is very comfortable and yes, very sweet to look at! – Yes, me like! A lot!

BIG thank you to my local Jaeger-LeCoultre AD – Nymans Ur 1851 for letting me handle this beauty!
To read more about the Master Calendar 2020, I recommend you to visit the Jaeger-LeCoultre home page.
Stay tuned for more…