This was the case from my brother in law:
Does your passport show any expiration date? Do you mean the visa ? yes it has an expiration date
After you receive your passport back, how long do you have to land? On their case they Have only 3 months to pack and move, because the medicals will expire, so depends is not written on solid stone, but I don;t think they will gave you less than 3 months to move so can be from 3 months to 1 year, that will be my guess.
Also, how long did they stay with your passport? Also every case is different, my brother in law go to Buffalo on Monday to drop the passport and he return the next day to pick up the visa, he didn't send them by mail he went himself.
Hope this helps!
Peace!