What you need:
A big log
How to play: Everyone stands on the log. When the leader says to be quiet, everyone has to be slient for the rest of the game. Without speaking or getting off the log, everyone has to get in order of their birthdays from January to December. You can use your hands to signal what your birthday is. If someone crouches down, then someone can step over them more easily. When they think they have it all in order they tell the leader.