Finding Overlapping Data
 

I have 2 worksheets with forecast data on them, one (the May forecast) covers
Q4 of 2005 to Q1 of 2007 and the other (the June forecast) covers Q3 of 2006
to Q4 of 2007.
I also have a third sheet, called "Combined" where the May and the June
forecasts are combined. How would I find the range on this third worksheet
where the dates for each forecast overlap?