If its a string, just do something like:
date = date.toString();
date = date.replace(/\([A-Z]+\)$/,"");
You could also change the format by passing in a new value to date.toString("%format%"), as per:
http://msdn.microsoft.com/en-us/library/az4se3k1%28v=vs.110%29.aspx
..but for what you need, simply doing the replacement would be the easiest :)