Why does your birthday change each year?

Answer 1

If your birthday never goes back to the same exact day like a Tuesday then you were born on a leap year. But the reason it changes is the affect of leap year especially because of the days all move forward each year look at your calender the next time you can then you will see that it will keep moving forward. It moves all over the week.

Answer 2

you have a birthday once a year because your month and the day you were born only comes once a year every tear.

Answer 3

because there is an odd number of days in a year.