几个月？还是自己主动提出来？

really depends, some sponsor as long as hiring you, some after hiring half year, some after one year, some never.

better ask when you think you do a good job and a must-needed guy in company.

一般基本上还是要自己提出来的. 选自己立下功劳的时候比较好.

I began mine after the probation