convert date into iso format code example

Example 1: date().toisostring().slice(0 10) giving wrong result

//Add Z in the end for getting the correct value with local timezone
var a = new Date("June 08, 2018 Z");
var res = a.toISOString().slice(0, 10);
console.log(res);

Example 2: iso to date javascript

date = new Date('2013-08-03T02:00:00Z');
year = date.getFullYear();
month = date.getMonth()+1;
dt = date.getDate();

if (dt < 10) {
  dt = '0' + dt;
}
if (month < 10) {
  month = '0' + month;
}

console.log(year+'-' + month + '-'+dt);