nifty idea for a reusable, customizable calendar.
Didn't take long and didn't cost much. (Depends on how fancy you want your calender to look)
I also turn it into a TO-DO list. I replace the calendar background with a blank sheet and write to do on it. Then write on the glass my tasks- each time I complete a task I wipe it off. And use different colours (red for things that need to be done ASAP etc)