回复：What's the legal start date for a H1B changer?

The company lawyer sent my application to the USCIS last week. The company told me that I could start the new position at the second day after ting the application. I don't think so. My question is what's the earliest legal date to start the new position, after receiving the reciept or the approval notice? I need to estimate the end date of my current employment.
-The nonprofit company lawyer is right. You can start to work after the H1 transfer is filed.