Format JavaScript date as yyyy-mm-dd

Question

I have a date with the format Sun May 11,2014. How can I convert it to 2014-05-11 using JavaScript?

Answer 1

Reformatting a date string is fairly straightforward, e.g.

var s = 'Sun May 11,2014';

function reformatDate(s) {
  function z(n){return ('0' + n).slice(-2)}
  var months = [,'jan','feb','mar','apr','may','jun',
                 'jul','aug','sep','oct','nov','dec'];
  var b = s.split(/\W+/);
  return b[3] + '-' +
    z(months.indexOf(b[1].substr(0,3).toLowerCase())) + '-' +
    z(b[2]);
}

console.log(reformatDate(s));