Mac Forum / Applications / Excel / June 2006

What function/formula can I use to return the previous month. Let's say cell
A1 contains the word  August.  What can I put in the next cell to return
July. But will also give December if January is in A1.  I am currently doing
it with the following convoluted vlookup & I'm sure there must be an easier
way.

ColG  ColH      ColI
   
12  December    12
11  November    11
10  October     10
9   September   9  
8   August      8  
7   July        7  
6   June        6  
5   May         5  
4   April       4  
3   March       3  
2   February    2  
1   January     1  
0   December    0  
-1  November    -1
-2  October     -2

Above is my vlookup range (columns G,H,I rows 3 to 17) and my formula is:

=VLOOKUP((VLOOKUP(A1,$H$3:$I$17,2,FALSE)-1),$G$3:$H$17,2,FALSE)

It works fine but I know I must be missing something *really* obvious.(and
simpler:-)

Many thanks

-Jay-