Given the success of these chronographs, it's easy to imagine that the établisseurs - the name given to companies such as Breitling, Heuer, Doxa, Le Phare, Léonidas, Record and many others that didn't manufacture their own movements - must have put pressure on Ebauches SA to produce chronograph-calendar calibers. The response was late but massive.
The first chronograph-calendar caliber offered by Ebauches SA was the Valjoux 72C in 1946, followed by the 88 the year after. But by 1948, the trust's two other ebauches chronograph manufacturers, Vénus and Landeron, were offering no less than 13 new calibers with calendar, and 10 more in 1950 [2]!
Numerous combinations were available: date, day, month, moon phases, date by central hand, date by hand at noon or 6 o'clock... Vénus even offered an additional rattrapante, while Landeron offered an original way of setting calendar functions: a mechanism managed by a rotating bezel, which did away with the unsightly little pushers on the periphery of the case.