js时间格式的转换

/date(******)/ 怎么转换为 2014-12-11 ?

function dateFormat(date, format) {
    date = new Date(date);
    var o = {
        "M+": date.getMonth() + 1, //month
        "d+": date.getDate(), //day
        "h+": date.getHours(), //hour
        "m+": date.getMinutes(), //minute
        "s+": date.getSeconds(), //second
        "q+": Math.floor((date.getMonth() + 3) / 3), //quarter
        "S": date.getMilliseconds() //millisecond
    }

    if (/(y+)/.test(format)) {
        format = format.replace(RegExp.$1, (date.getFullYear() + "").substr(4 - RegExp.$1.length));
    }

    for (var k in o) {
        if (new RegExp("(" + k + ")").test(format)) {
            format = format.replace(RegExp.$1, RegExp.$1.length == 1 ? o[k] : ("00" + o[k]).substr(("" + o[k]).length));
        }
    }
    return format;
}

调用：dateFormat(date, 'yyyy-MM-dd hh:mm:ss'),