This travel season, many applicants were turned back at the airport while trying to board a flight because their passports did not have at least six months of validity left in them. Many countries around the world have instituted this six month rule, which requires that travelers have at least six months of validity left on their passports at the time of arrival. Any applicant without six months of validity must get a new passport in order to meet that country's entry requirements. For some countries requiring a visa (e.g. India) the requirement is related to the validity left at the time the applicant applies for entry visa.
To determine a destination country's entry requirements go to the passports section of the travel.state.gov, find the "county information" tab (https://travel.state.gov/content/passports/en/country.html) and search by country. The foreign country entry requirements booklet is NO LONGER being produced.