DieselDaddy and I were trying to help DieselBaby understand when things were going to happen - like church, swimming, treats. Unfortunately, toddlers can't really understand "you will go swimming on Sunday/4 days". So we came up with a chart so he could visually see when he would be able to do something.
I originally had the numbers 1-5 (the days he goes to school), but I found it easier to say "you have 3 more school days until...."Now, we say "Today is Tuesday, Orange day. That means you will go swimming on Sunday. Pink day. How many days until swimming?" The visual has also helped cut down on the whining. "I want a treat" We tell him to go look at his calendar and tell us how many more days until he can have a treat.
After doing it for a few weeks, I actually found myself dressing him in the colors of the day. It doesn't always work that way, but....
Best of all...I used things I had on hand :)