回複：Thanks! doshexh. I still have another concern

It is based on the date of H-1 from INS, not your pay check from your school. Also, you can some reasonable gap between first and second H-1b. That's why i siad when you submit your second H-1b, you can go for work. The receipt may come later. The real second H-1 approve date maybe even late (which mostly based on your school petition date, in my case, the real date was later then my school required date, e.g., my school required date was 6/1, but I got approved date 6/10, whcih should have no problem, because that was within reseanable peoriod). How long is the "reasonalble periord"? No exact definition for that.