How can I change the first day of the week in FullCalendar?

 firstDay

The day that each week begins.

Integer, default: 0 (Sunday)

The default value depends on the current lang.

The value must be a number that represents the day of the week.

Sunday=0, Monday=1, Tuesday=2, etc.

This option is useful for UK users who need the week to start on Monday (1).

Solution:-

  $('#calendar').fullCalendar({
        .......................................
        firstDay: new Date().getDay(),
        ....................................................
});