Calculation of six years on H1B

[absdesai]

Hi
Is the six-year period calculated from the time of entry into the country or from the date the H1B approval notice was issued?
For instance, my H1B approval came in December 2000 but entered the country in March 2001.
Thanks,
Aparna

 

[GotPR?]

It starts upon your entry to the US.