ændre dato formatet til yyyy/mm/dd

ref http://stackoverflow.com/questions/3552461/how-to-format-a-javascript-date
var today = new Date();
today.toLocaleFormat('%d-%b-%Y'); // 30-Dec-2011

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleFormat

...


Plain JavaScript is best pick for small onetimers.

On the other case if you need more date stuff, MomentJS is a great solution.

for example:

moment().format('YYYY-MM-DD HH:m:s');    // now() -> 2015-03-24 14:32:20
moment("20111031", "YYYYMMDD").fromNow(); // 3 years ago
moment("20120620", "YYYYMMDD").fromNow(); // 3 years ago
moment().startOf('day').fromNow();        // 11 hours ago
moment().endOf('day').fromNow();          // in 13 hours


http://momentjs.com/

Så er den der.. tusind tak..

toLocalFormat er ikke crossbrowser sikkert.

Hvis det bare handler om dette lille eksempel, er det måske overkill at inkludere moment biblioteket. Man kan rimeligt hurtigt lave den selv:

var d = new Date();
var dDate = d.getDate();
var dMonth = d.getMonth() + 1; //Months are zero based
var dYear = d.getFullYear();
document.getElementById('fejl_date').value = dYear + '/' + dMonth + '/' + dDate;