Help with =TEXT(A40,"m/d")&"-"&TEXT(A40+6,"m/d")

1. I have a date in cell A40 (7/21/2013).
2. On cell D2 I have the formula =TEXT($A$40,"m/d")&"-"&TEXT($A$40+6,"m/d") to display 7/21-7/27.
3. My dillema is how to increase the date range (7/21-7/27) by 7 days in the subsequent columns (E2 to Z2) i.e. E2(7/28-8/3)| F2(8/4-8/10)| G2(8/11-8/7).....Z2.

I have tried putting =((A40)&"-"&(A40+6))+1 in E2, but it gives me #VALUE! When I put =(A40)&"-"&(A40+6) in cell D2 it displays 41476-41482, which is the date value.

This is my first post, and I am thanking anyone in advance. I am using this format for my Production and Sales forecast.

Try this formula in D2 copied across

=TEXT($A$40+COLUMNS($D2:D2)*7-7,"m/d")&"-"&TEXT($A$40+COLUMNS($D2:D2)*7-1,"m/d")