[解決済み] JavaScript の日付を yyyy-mm-dd でフォーマットする。

function taskDate(dateMilli) {
    var d = (new Date(dateMilli) + '').split(' ');
    d[2] = d[2] + ',';

    return [d[0], d[1], d[2], d[3]].join(' ');
}

var datemilli = Date.parse('Sun May 11,2014');
console.log(taskDate(datemilli));

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('-');
}
 
console.log(formatDate('Sun May 11,2014'));