回复：My experience

I have experienced same situation two years ago. I was transfered within departments in the same university. (Didn't know why our Internationa office insisted interdepartment transfer needed new H-1B.) Petition mailed out early Dec. Receipt back middle Dec. Started next Jan. Approval back early March. I STRONGLY suggested you should advise new employer to send now so you can get receipt before new year. Our international office told me that within valid period my previous H-1B won't expire until I received new H-1B.