We make one every year around this time. A paper chain to count down the days, with special holidays and occasions in a different color. We started the tradition 2 years ago as a way to give my daughter a better grasp of time as we counted toward the days of her little brother's birth. All of our birthdays fall right in a row and having a colored chain that the special days stand out in really helps her grasp the order and length of time. Mom's birthday (yellow), Halloween (orange), Daughter's birthday (pink), Thanksgiving (orange again), Dad's birthday (green), Son's birthday (blue), Christmas (red). All the "regular" days are the same color, this year it's purple.
We use other calendars and count-down activities too, but nothing quite compares to the fun of the paper chain!