When using the methods of other answers, the configured options are lost, to correct it, you can use a global configuration:
$('.datepicker').datepicker();
$.fn.datepicker.defaults.format = 'dd/mm/yyyy';
$.fn.datepicker.defaults.startDate = "0";
$.fn.datepicker.defaults.language = "es";
$.fn.datepicker.defaults.autoclose = true;
$.fn.datepicker.defaults.todayHighlight = true;
$.fn.datepicker.defaults.todayBtn = true;
$.fn.datepicker.defaults.weekStart = 1;
Now you can use the update method without losing the options:
$(".datepicker").datepicker("update", new Date("30/11/2018"));