TypeError: d is null when using set method

[yazilim-crmturizm]

Got an error TypeError: d is null when try to use "set" method
Ex.

$('.datepicker-end').pickadate({
    format: 'dd.mm.yyyy',
    min: new Date(),
    editable: false,
    onSet: function(context) {
        $('.datepicker-start').pickadate('set','min',new Date(context.select));
    }
});
$('.datepicker-start').pickadate({
    format: 'dd.mm.yyyy',
    min: new Date(),
    editable: false,
    onSet: function(context) {
        $('.datepicker-end').pickadate('set','min',new Date(context.select));
    }
});