You need the health certificate to be within 10 days to verify the dog is healthy enough to travel. Look at your rabies record and see if it was a one or two year vaccine, they have both. If its a two year then its two years, if its a one year then its one year. If it dosnt say consider it one year and yes at least 30 days prior to entering the country.
Its very important to have your permit for the dog to come into the country in hand. Dont count on it to be waiting for you at the BAHA airport office. My friends were charged $400 for their small dog. Without the paperwork in hand.