To make a fun display of students' birthdays, simply print out these pages. Included are labels for each month and blocks spelling out
B-I-R-T-H-D-A-Y-S. Take pictures of your students (grouped by month) holding up signs showing their birthdays. Put each picture below each month label.
I am thinking of doing this on the door to the hallway. January-June will go down the left side and July-December down the other. The blocks will go down the middle. (See Pinterest for some examples.)