Question on China tourist visa, double entry visa with 3O days duration for each stay

i got tourist visa, double entry visa with 3O days duration for each stay and valid to enter before june 10, 2011. i used my first entry last month. im planning to come back to beijing on tuesday May 31, 2011) and come back to my country (Philippines) on 13th of june 2011. i am confused. my question is, is it posible for me to stay until june 13th since i will arrived beijing on May 31st, since written on my visa that "enter before june 10th"?

Do you have any hotline to call?

Hoping for your immediate response.
Thank you!