According to All Things Target (yes, this is a real website), there's a markdown schedule for the stores. It may vary by location, but you get the gist:
Each week, Target marks down items in departments depending on the day. The article says that most markdowns will be 30% off to start, move down to 50% after two weeks or so and then finally, the items will be marked down to about 70%...what a steal!
Visit (this link) from All Things Target to get more of an explanation. Here's a pretty cool graphic that the site has regarding the days that things get marked down, as well!!