score:1
You will not have an extra two months.
The visa is valid once it is issued; even if you do not utilize (ie, travel) on the visa.
Unless canceled or revoked, a visa is valid until its expiration date. Therefore, a valid U.S. visa in an expired passport is still valid. If you have a valid visa in your expired passport, do not remove it from your expired passport. You may use your valid visa in your expired passport along with a new valid passport for travel and admission to the United States.
A visa is a permit to enter the country. It is also not a guarantee of entry (you can still be denied by border control even if you hold a valid visa).
Generally on a B1 visa, once you enter the country - you are allowed to stay for 6 months (sometimes, up to a year on entry).
For example, you get a visa on July 1st valid for 6 months; you can travel anytime between July 1st and December 1st - after December 1st, your visa is no longer valid (even if you did not travel on it). It does not matter if you fly on July 2nd, or November 2nd - the visa expiry does not change.
Upvote:2
The validity of the visa is unrelated to the allowed length of stay. One consequence if this is that you can travel to the country and seek admittance any time up to and including the day on which the visa expires. Another consequence is that you might be issued a visa valid for 10 years; that does not mean you can stay in the US for 10 years. Each time you enter the country, the border officer will indicate in your passport how long you may stay during that visit.
Upvote:3
The USA (unlike for example schengen) has seperate concepts of "Visa" and "Status".
A visa lets you travel to the border and request entry into the corresponding status. Assuming you are granted entry the status then lets you stay.
Normally a B1/B2 visa (plain B1 and plain B2 visas are rare) has a validity between one and ten years.
A B1 or B2 status on the other hand normally lasts 6 months. It is possible to apply for an extension of status to extend that though it's rather expensive and not gauranteed.
With the exception of short visits to Canada, Mexico and a few other nearby countries your status ends when you leave the USA. If you return to the USA while your Visa is still valid and the immigration officer belives you are still a legitimate visitor then you will get a brand new status.
In the USA a status can outlive the Visa so if your visa is still valid at the time you enter you could in principle at least stay another 6 months.
There is no formal limit on the total length of consecutive visits but too many long closely spaced visits may make the immigration officers suspect you are not a legitimate visitor.