Porównaj dwie daty w JavaScript TRYYY-MM-DD

// Shows if one date is gerater than the other returns True/False.
var date1 = '2015-08-20 09:38:20';
var date2 = '2015-08-20 08:00:00';
var date1Updated = new Date(date1.replace(/-/g,'/'));  
var date2Updated = new Date(date2.replace(/-/g,'/'));
console.log(date1Updated > date2Updated);
Undefined