i once saw an article and list of month by month of major retail sales
by category such as photography, furniture, shoes etc. in a north
american newspaper. cant remember where..

ray-on-the-web,

My mom used to have a similiar list, so I know what you're looking
for.  I found it for you at a web site called "The Dollar Stretcher,"
where someone happened to ask a nearly identical question.

The list is long, so I won't list everything here, you can access it
at the link below and print it.  You'll need to scroll down a bit to
see the actual monthly list.  The whole page is interesting, be sure
to read it all!

The Best Time to Buy... 
http://www.stretcher.com/stories/980709d.cfm

Hope this helps!

~~Cynthia


Search terms used at Google:
"best time to buy" schedule store sales

perfect... thank you