X 2 Visa

Hi,

My daughter is a NYU Student and is going to do study abroad this Fall 2014.

We were told to get X2 visa which would be valid for 90 days from the issue date within which she has to enter China and can stay there for 180 days.

Can you please confirm the above. Also will there be any expiry date for X2 or it expires 180 days from the entry date into China.

Thank you in advance.

Sam