And I must say that the title is not helping a lot.
With that name, you think that the Duometre à QL is all about the moonphase, which is wrong.
It is not especially accurate with a deviation of one day each 2, 5 years, while others do much better with each 122 or even 1000 years!
The moonphase, here, I see it as an aesthetical pretext, nothing less, nothing more.
The real aim of this QL is... Accuracy, due or thanks to its construction: One barrel for the Time, the Date and the Moonphase, and one barrel for the... Escapement!
So, the escapement is not polluted by the time and th other factors, which is pretty brilliant.
Best,
Nicolas