[flexcoders] Flex 2.01 date problem

[aceoohay]

The following code yields unexpected results on a date;

                        var dtTest:Date = new Date;
                        dtTest.fullYear = 1987;
                        dtTest.month = 1;
                        dtTest.date = 3;
                        trace('dtTest.toDateString()=' + 
dtTest.toDateString());

The result is;

dtTest.toDateString()=Tue Mar 3 1987

It is my understanding that this should be February not March. What am 
I doing wrong? or is there a bug in the Date object?

Paul