Design your own calendar is a fun way to reinforce calendar concepts. Have your students draw a picture to represent each month, fill in the dates, and add special events to their calendars (birthdays, holidays, tests, etc).
You can use this during morning work time, independent work time, or during math centers. Ask your students math questions and have them answer the questions by coloring in certain dates.
You can also have your students use each month as a homework log or have them decorate it for a gift. There are so many possibilities!