他护照上移民签证的入境章是去年11月2号，但是他是去年12月25号离开的美国。
他需要在11月2号之前，还是12月25号之前返回美国呢？
-It is before Dec. 25, but the earlier the better. You don't want to let the IO doubt his intent to live US permanently. The IO at the port of entry has the right to cancel his green card even if he returns to US before his stay in China reaches one year.
谢谢!
