You can also subtract an hour or add an hour. I used some of the above code and changed it to the format I needed. Thanks for the above example. It really helped me get the below working :)
// get a date in the current timezone
var date = new java.util.Date(qie.deduceDate(source.getNode("OBR-6")).getTime());
// convert the above date to new Date(won't work without doing this)
var olddate = new Date(date);
// subtract 1 hour
var newdate = new Date(olddate.getTime() - (1*60*60*1000));
// create a SimpleDateFormat object
var date_format = new java.text.SimpleDateFormat("yyyyMMddHHmmss");
// insert new date to wherever you want
message.setNode('OBR-6', date_format.format(newdate));