Last date of my Type F visa

I am visiting Guangzhou, China on 15 May, 2018 and I have been issued a Type F for 30 days from date of entry. I shall stay in Guangzhou for a 1 month student programme that ends on 14 June, 2018. I want to know the last date of my 30 days Type F. Will it be 13 June 2018 or 14 June 2018? Do I need to apply for extension? My return flight to India is on 15 June 2018. Please help quickly as I have to leave for Guangzhou on 14 May 2018.