function getDefaultDate(curDate){
var dt = new Date(curDate);`enter code here`
var date = dt.getDate();
var month = dt.getMonth();
var year = dt.getFullYear();
if (month.toString().length == 1) {
month = "0" + month
}
if (date.toString().length == 1) {
date = "0" + date
}
return year.toString() + "-" + month.toString() + "-" + date.toString();
}
In function pass your date string.