China Chao, are you in a middle or primary school? When I was in a senior middle school, I got a good two months off. My oral English classes stopped before the end of the semester because the students had to study for exams. Then they had exams, but not for my classes. After the holiday they'd go back early for extra lessons; again, for the important classes - not mine. My Chinese co-workers were responsible for all of this stuff. Meanwhile, I got paid for not working.
I'm in a uni now. My classes and exams will be over during Christmas week. Our official holiday is Jan 16 to Feb 28. Classes begin again on March 1st. The official summer vacation begins on July 10th.