I had always received payment on the 20th of the following month since I started shopping for this MSC in 2013. There was one situation where payment was not received the next month....when I inquired about it, I was told that this was a client that was on a 60 day pay cycle rather than 30 days.
This was early last year, and other than that one client, I have always received payment on the 20th the following month.
I just got a payment yesterday in PayPal for my Feb. Shops.