Days between H1b approved and employment starts (cap exempt)

[Quuzuu]

I'm currently on F1 OPT, I worked for 9 months but was unemployed. My accumulated unemployed days will reach 90 days on 12/24, meaning I will be out of status on 12/24, no grace period.

Now a university research lab (cap exempt) will sponsor H1B for me, and they will mail out the application before 12/24. They are also applying for premium processing for me (15 days between USCIS receive the application and the decision is made). My work start day is set at 2/1/2014.

My question:

1. If the H1B application is approved before 2/1 (which is very likely to happen), say 1/15, am I in trouble between 1/15 and 2/1? What should I do during that time?

2. If we set the employment start date at 1/1, does it resolve the problem?

3. If we try our best to mail out the application before 12/24, but can't make it, and end up mailing it out on 12/29, technically I'm overstaying for 5 days, will I be fine? In this case, what's the date that matters? The postmark? The petition filing date on the form (signature and date)? Or the date that USCIS receives it?

Thank you very much!!!

[ramz]

Days between H1b approved and employment starts (cap exempt)

The date USCIS receive and send you the acceptance notice to your email and hard copies follows.