Why Lidl and Aldi remain closed on Sundays while Delhaize and Carrefour do open

The supermarket war rages on and one of the hottest issues is the Sunday opening. While chains such as Delhaize and Carrefour, through their independent stores, quickly open their doors on the last day of the week, Lidl and Aldi keep their stores closed and ask for a level playing field in the supermarket sector. What exactly is going on?

ttn-3