function Unix_timestamp(t) 

{

    var dt = new Date(t*1000);

    var Y = dt.getFullYear();

    var m = (dt.getMonth() + 1)+"";

    m = m.length == 1 ? "0" + m : m;

    var d = dt.getDate()+"";

    d = d.length == 1 ? "0" + d : d;

    return Y + "-" + m + "-" + d;

}

var test = Math.floor(new Date('2019-03-05').getTime() / 1000);

console.log(test);

var s = Unix_timestamp(test);

console.log(s);