When are the main 5 (characters) birthdays (the month) and how does it go oldest to youngest?

because on the naley spot i heard that haley is 17 when she grads. and then in 5x04 is still 21. so someone dicho that haley skipped a grade. and it makes no sense to me. so i just wanna see oldest to youngest nd their bday. :D

nd were the 5 main characters born in '86??