It's not uncommon for stores to have sales - especially around "holidays". They have Valentine's Day sales, President's Day sales, 4th of July sales Summer Solstice sales, Winter Solstice sales ... my Grandma made a poop without prunes sales! And, when they get overstocked on certain items.
The biggest usually start with the pre-thanksgiving sales ... after that you get the pre-Christmas .... and the end-of-year after Christmas but before new years day sales.
If you want to know what the monthly specials from a particular store are - you'll just have to spend a few months watching what they put on sale. I know I got some AC multi-cookers from a website a few years ago that have not been that cheap again.