These docs are for an old release.
Info on upgrading to v4
Methods
Methods provide ways to manipulate the calendar from JavaScript code. A method operates on the jQuery object of a calendar that has already been initialized, using the familiar fullCalendar command, but in a completely different way:
$('#calendar').fullCalendar('next');
This will call the next method and will force to the calendar to move to the next month/week/day.
If you want to avoid using jQuery each time you call a method, you can do something like this:
// a convenient utility for getting the calendar object.
// you can call methods on the calendar object directly.
var calendar = $('#calendar').fullCalendar('getCalendar');
calendar.next();