[2023] Missing calendar key in the event

Mysterio said: Oh ****, I missed it ... thank you, by the way ...
But when @Juber says "roughly", he means it's only a low probability (around 1/3) to have one .... so we can pass 10 boards without any key, isn't it ?

This can happen. You can also have 10 boards in a row with a key.  

This is a bug thread, locking it.