Dear Experts,

I came to US at Aug. 15 2001 with F1 visa. Now I am working under OPT through 9/30/2006. Should I pay SS&Medicare tax?

In Pub519 "You will not be an exempt individual as a student if you have been exempt as a teacher, trainee, or student for any part of more than 5
calendar years unless you establish that you do not intend to reside permanently in the United States and you have substantially complied with
the requirements of your visa."

How to calculate the 5 calendar years? If calculate from 8/15/2001, then I should not pay SS&Medicare until 8/15/2006, right? If calculate from 1/1/2001, then I should pay tax after 12/31/2005, right? WHICH ONE IS CORRECT?

Thanks!

Inong:

Calculate the five year period for Social Security and Medicare tax liability starting with 15 August 2001 through 14 August 2006. If you are still in country on 15 August 2006, have your employer begin withholding Social Security and Medicare taxes on that date.