If you ever want to visit Calgary but don't know when, Stampede week is your best bet. It might be pricey to visit during Stampede week but it's a lot of fun, so it's worth it. I've lived in Calgary almost all my life and I gotta say, this is my favourite time of the year. The only thing is that it's quite expensive and most vendors don't take debit or credit cards. I normally go for the food, games and rides. If you like donuts, you honestly need to try their mini donuts, there are a bunch of booths all over the grounds so you can't miss it. If you plan on going on the rides, buy a wristband at the grounds or at a Mac's store because it's a lot cheaper than buying tickets.
The only thing I really hate about being there is the amount of people at the grounds. It can get extremely hot because there's way too many people and lining up for food and rides is definitely not fun.