I created this website http://peace-in-the-city.be/en/book-now and on that page you will see I used a Calendar to show the availability of the apartment. ( http://drupal.org/project/availability_calendars )
I tried to let the calendar start on Monday. I googled for the solutions and did change my regional settings local to start of the week to Monday. It worked after that for a couple days. But for some reasons it went back to Saturday. Changing the regional setting has no effect anymore now.
At this point, I'm clueless... Any tips, links and ofcourse working solutions are welcome.
PS. I did not change anything in the rAvailability Calenda module. I'm just install modules - enable/disable - or change configuration.