Wednesday..release?

There will be some Single/Album release on the next few days.. and it will be on Wednesday November 14 (KinKi Kids, L'Arc~en~Ciel, Hey! Say! JUMP), and Wednesday November 21 (L'Arc~en~Ciel, ONE OK ROCK). I checked, and apparently, Hey! Say 7 first release was on August 01 and it's on Wednesday. GLAY latest single also released on Wednesday October 31.
So, it's all about Wednesday. But why? Any business thing behind it? Am I the only one who didn't know anything about it?

In my place, similar happened, like for launching a new product, etc. will be held on Friday. There;s business reason also superstitious behind it :D