I am currently working for Company A under H1-B (starting Oct 1, 2013) and have secured a job with Company B. Company B has already filed for my H-1B transfer and told me that the rule is you can commence employment with your new employer once your H-1B change of employer/petition is received by US Immigration for processing. I have already given a notice to my current employer which ends on March 12th. They have been kind enough to let me work after that if I want to. However, they need a specific end date.
My question is if I leave Company A on March 12th and then join Company B whenever the receipt comes (hopefully no later than March 17), is it legally fine if I have a gap between my end date at A and start date at B? If not, I will confirm my end date with A to be March 12th