Actionscript 3 :: Listening To Changes Made To Flex Date Object?

I have a date object and I want to listen to any changes made to it. The changes can be made by either directly assigning another date object

var newDate:Date = new Date(2009,10,9);
date = newDate;

and by using

date.setTime(timeInMilliSeconds)

I tried using BindingUtils.bindsetter:

var myWatcher:ChangeWatcher = BindingUtils.bindSetter(updateDate,date,"time");
private function updateDate(value:Number):void
{
trace(value);
}

but this doesn't seem to work. I wish to know what am I doing wrong or if there is someother way to do this.