How to change the calendar's first day of the week in the Events module

In order to change the week first day from Monday to anything else: 

1. go to  /application/modules/events/views/flatty/helper_search_form.twig 

2. add firstDay: 7(1-7 depending on the day you want to have) in the calendar js 

3. Done! Now you have changed the calendar 👍