Most of us probably check our passport prior to a trip to assure it is valid. Actually you need to go one step further ………. you need to check the requirements of any countries that you might be visiting! Some have requirements that your passport be valid for 6 months from date of entry while others may be 30, 60, or 90 days. If you passport expires prior to the requirements you might not be allowed into their country.
As a rule I try to assure we always have a minimum of 6 months validity on our passports and depending on travel plans we may renew much earlier. While you can expedite a passport renewal it does cost extra and can be stressful if you are on a tight timetable!