H4 visa interview on the basis of H1 approval

I have my H1b application done by my employer this year and I am awaiting response from the USCIS. My question is if I get an approval from the USCIS, can I make my wife stand for an H4 visa interview before the effective date of my H1b (which would be oct 1,2013 ) ? Another part of the question is if at all she can and she gets the visa stamped, can she come to US before my H1b effective date…,i.e…can she come to US before oct 1 or she has to wait till october 1 by the time my H1b gets into effect? Thanks

Yes, you can. H1B VISA interviews can be scheduled atmost 90 days in advance to the work start date, that is July 1st 2012. I believe, that holds true for H4 interview appointments as well. So your wife can attend H4 interview any time after July 1st (and ofcourse after your H1B approval).

As per rule, H1B work start date is 1st October and the earliest the person can enter into US is 10 days prior to that, that is 20th September. I think this is the case with H4 VISA holder too. Moreover, H4 is a dependent VISA attached to a person who is in H1B status. So your wife might have to wait till you are moved to H1B status which happens only by 1st October. No one can be in US on H4 status without the primary non-immigrant in H1B status.

Hope that helps.