Working with StartDate and EndDate calendar fields

I have a LiveCycle form with two calendar fields,  StartDate and EndDate.  Whenever I open up either calendar they open up to today's date.  That is fine with the StartDate field, but if I change the StartDate to pick a date two months from now I would like the EndDate calendar field to open up to at least the same date as I chose in the StartDate field (not today's date).  Any help would be appreciated.