Here you can find the source of timestamp()
Date.prototype.timestamp = function () { return this.date() + " " + this.time(); };
Date.prototype.timestamp = function(){ return Math.floor(this.getTime() / 1000); };
Date.prototype.timestamp = function(){ var h = this.getFullHours().toString(); var m = this.getFullMinutes().toString(); return h+':'+m+':00'; };