Enable specific dates in bootstrap datepicker widget

datepicker.js

/*
Create case: you want to enable only the future dates and disable the past
Update case: you still want to enable future dates but enable only the the past date already stored in the db
*/
var now = moment(moment().format('DD/MM/YYYY'), 'DD/MM/YYYY');

$('#bulk-sms-form #start_date').datepicker({
    format: 'dd/mm/yyyy',
    beforeShowDay: function(date) {
        var current = moment(date);

        return current.isSame(moment('{{$messageConfig->start_date}}')) || current.isSameOrAfter(now);
    }
});