A. Lange & Söhne Perpetual Calendar Comparison

The Perpetual Calendar is one of the fav complications from Lange. It can be found in several models, most of them using the big date display. But when the 1815 Rattrapante PC was unveiled, Lange & Söhne has started to use a different way to display the date by using a hand in a subdial. Lange offers distinct dial lay-outs to display the Perpetual Calendar data, the most traditional in the Lange environment comes from the Langematik Perpetual.

The most original lay-outs are offered by the dials of the Richard Lange Terraluna and the Lange One Perpetual Tourbillon. The latter features an unique, in the Lange context, peripheral months display based on a rotating disk which jumps  instantaneously at the end of the month... like the other displays. The months are displayed by a window on the Terraluna dial.

What is my fav watch of this selection? It is without any doubt the first one, the Langematik Perpetual. I find it the most practical since it combines the big date display and an automatic movement. You may argue that the Lange One Tourbillon does the same. Yes but there is also a tourbillon and this addition makes the Lange One very expensive. And the Langematik also has a winning point: the automatic movement is the Sax-O-Mat with the 3/4 rotor while the winding mass of the Lange One is a central one.

 In the end, the big asset of the Lange Manufacture is to be able to offer these different ways to master the complication and whatever are your tastes, it is almost mandatory for you to find an appealing Perpetual Calendar watch!

Let's have a close look on each one.


We forget it very often but this Langematik Perpetual features a clear day&night display which is very useful when it comes to set the time and the Perpetual Calendar data (the tiny hand found is some other pieces is also very convenient). It offers the traditional Lange way to display the information with a large date on top of the dial (the date is the most important display in a Perpetual Calendar watch since all the other displays are used to set the correct date). I have a soft spot for this watch and its beautiful movement. Of course, its performances are not at the same level than with a more contemporary movement: for example, the power reserve is only at 46 hours what can be considered as low according to today's standards and especially for a Perpetual Calendar watch. But who cares? In a collector's point of view, the practical side is not the most important. The beauty of the movement and its consistency with the spirit of the Manufacture are more important. And the Sax-O-mat remains the most beautiful automatic movement from the Lange manufacture. The case  is very balanced with a 38,5mm diameter. It is the reason why I find the watch elegant on the wrist and the dial lay-out close to perfection.




The 1815 PC Chronograph is a bit the opposite watch:it is large (41,9mm), it displays the date with a hand and it is powered by a handwind movement. However the power reserve remains low (42 hours) and it becomes here a more salient issue because a winder can't be used.

Anyway, this 1815 is a gorgeous piece. First of all, I like its pocket watch spirit enhanced by the very classic dial lay-out. The chronograph data are well integrated on the dial and I like the way the minutes counter and the power reserve are located on top of the dial. They are after all very useful indications. The rattrapante pusher is on the left case side.

The movement organization is distinct from the DS one: the bridges seem to be flatter and I don't experience the same feeling of depth. But it is, like any Lange chronograph movement, a pure feast for the eyes.



The Richard Lange Terraluna is a very specific watch in this selection. To be honest, when it was released, I fell totally in love. But I am less convinced now. It is obviously an impressive piece with a spectacular caseback, unique in the Lange context. But I find now its dial a bit too confusing (despite the use of a large date) and the case is very thick (16,5mm) for a 45,5mm diameter. This watch is not for the small boys and it is also very heavy.

Having said that, I recommend it for those who look for a powerful design. Moreover, this watch features the largest power reserve from Lange (14 days) if I put aside the Lange 31 days which needs a key to be wound. The leap year is indicated by a window. 



The Lange One Tourbillon PC is another big piece even if I find it quite reasonnable compared to the Terraluna. After all, its case diameter (41,9mm) and thickness (12,2mm) are not so large considering the gathering of complications. This watch introduced the instantaneous jumping date system and since it is a Perpetual Calendar piece, it did the same with the other displays.

The watch is powered by an automatic movement with a central rotor. This type of movement was mandatory due to the presence of the tourbillon on the back. A movement based on the Sax-O-Mat was not possible and the winding mass had to overlap the full surface. It is not a surprise: the dial lay-out is similar to the Lange One Daymatic with the time display on the right and the days display on the left. The peripheral months display makes us think about the cities of reference of the second timezone of the Lange One timezone. It also jumps instantaneously at the end ot the month and this feature required an exclusive development of the movement: the system saves the energy which is demanded to make the disk rotate and releases it at once without disturbing the timekeeping of the watch.

The power reserve is not very large (50 hours) but a winder can be used.



Back to a more classic display with the Datograph Perpetual. We recognize the Langematik Perpetual one even if the chronograph data were added. The second hand moved to the left subdial and the minutes counter was added around the right subdial. On the downside, I don't like the "isolated" small moonphase display and I would have loved a larger opening.

The case diameter is 41mm and the thickness is 13,5mm (which is just 0,4mm more than the Datograph Up & Down case). The power reserve is low (36 hours) and I would have expected to see Lange to apply the power reserve enlargement of the Datograph also on this piece. My fav version is the white gold one with slate grey dial and I consider it among the most appealing Lange watches.



The Datograph Perpetual Tourbillon offers similar proportions with a 41,5mm diameter and a thickness of 14,6mm. The dial lay-out is also identical even if the day&night and the leap year indicators are not displayed exactly the same way. The key feature of the watch is the movement which was fully redesigned in order to integrate the tourbillon by keeping a very close case size to the Datograph Perpetual One.



I would like to finish this selection by the latest handwerkskunst piece from the Manufacture. It is not the first time a Perpetual Calendar watch is offered in the handwerkskunst context (the Lange One Tourbillon was previously subject to this decorative approach) and I was a bit afraid by the outcome when I learnt that an 1815 Rattrapante PC handwerkskunst would be released. But Lange did a great job especially dial side and on the movement: let's say I'm not a fan of the decoration and the aesthetic style of the lid.

This watch gives another proof that the Perpetual Calendar is a significant complication for the Lange team.



So with an automatic or a handwind movement? Accompanied with other complication or alone with the time display? With reasonnable case sizes or with larger cases? With a large date display or with a hand? Lange offers a lot of possibilities and maybe the SIHH 2018 would offer a new Perpetual Calendar piece? Honestly, I have no clue and maybe it will not be the case but considering the manufacture skills on this complication, I would not be surprised to see a new member to this family of Perpetual Calendar pieces. And if not, I have to confess that the range is already very versatile and wide!

I wish you a very happy new year and I hope that new Lange pieces will join your collections!

Fr.Xavier