Ah, no, sorry. This would be more like the opposite of that: An extension of carnival itself into a period of several months.

According to that timeline, carnival "really" begins on November 11 (11/11) with a one-day celebration, then goes on in a low intensity sort of way all throughout winter, to end with the celebrations of the traditional festival.

It seems to have been a 19th century invention and in effect decouples the celebration from its religious role.

https://de.wikipedia.org/wiki/Karnevalssession

Oh that is still a super interesting difference, thanks!