i got the error like this ..
help how to fix this error
You can make that using available date methods like this:
var d = new Date(1540995900000);
var date_string = d.getUTCFullYear() + '-' + (d.getUTCMonth() + 1) + '-' + d.getUTCDate();
Create a JavaScript function as following an just pass the date.
function formatDate(date) {
    var d = new Date(date),
        month = '' + (d.getMonth() + 1),
        day = '' + d.getDate(),
        year = d.getFullYear();
    if (month.length < 2) month = '0' + month;
    if (day.length < 2) day = '0' + day;
    return [year, month, day].join('-');
}