To be honest, I had never heard of the French satire magazine "Charlie Hebdo" before the recent terrible events in France, but as a fan of etymology (the study of the origin of words) I was able to deduce that the name had something to do with it being a weekly publication.
The word "hebdomadal" is not one we often see in wide usage, but I remembered reading it in one of Ring Lardner's essays from the 1920s, and I remembered looking it up. I found that it means "weekly," and comes from the late Latin hebdomadalis, and from the Greek hebdomas, meaning seven, or seven days. The French word for hebdomadal is hebdomadaire.
The "Charlie" part of the magazine's name came from two places. In a previous incarnation, it had been called Hara-Kiri as a monthly publication, and then Hara-Kiri Hebdo when it changed to a weekly. The magazine got in a jam when they printed a story that satirized the death of former French President Charles de Gaulle, and changed their name thereafter to Charlie Hebdo, which was also a nod to Charlie Brown, yes, that bald-headed kid from Peanuts, the American comic strip that ran in a sister publication in France, a comic compilation called "Charlie Mensuel" - Charlie Monthly.
Looking back, I realize that this explanation was only slightly less wordy and confusing that my explanations for my whereabouts when I was between the ages of 13 - 18, after which people stopped checking on me. Back then, I would get in some sort of trouble at least hebdomadally.