主题：F1/OPT转J1，RFE过程中收到Tenure Tra -- 流江河

is decided based on when your petition reaches the physical site of Service Center of USCIS.

For the purpose of H1b Lotter, even if it reaches the PO Box of USCIS but not physically on the site of the Service Center by 5 pm of April 7, 2014, the petition misses deadline.

But if your petition is received before 6 AM of April 1,it will be returned.

So typically H1b petitions were sent via UPS/Fedex/DHL/USPS on the evening of March 31,2014 or early morning April 1, 2014. Technically it is possible to file on early morning April 7, 2014, though the risk is high.

For other purposes, the rule is not that stringent. It is not the end of the world even if you miss one or two days. But don't do such sloppy things if you can do it professionally. The risks are too high to be justified.