You could try the "complete ()" method before using the values. From the api docco:
protected void complete(); Fills in any unset fields in the calendar fields. First, the computeTime() method is called if the time value (millisecond offset from the Epoch) has not been calculated from calendar field values. Then, the computeFields() method is called to calculate all calendar field values.
[ March 12, 2004: Message edited by: Eddie Vanda ]
The nice thing about Standards is that there are so many to choose from!