If you don't know when your U.S. passport expires, you might have an unpleasant surprise before your next trip. Depending on your destination, your passport may need to be valid for another three to six months before you can get on the plane. Want to read some horror stories? CLICK HERE.

If you're traveling in Europe, your passport needs to be valid for at least three months from departure.
Many Asian countries require a passport that is valid for at least six months from departure.

You can find out the rules for your destination by checking the U.S. State Department's website.

So now that you're thinking about this, take a moment to calendar a date for renewing your passport. Go ahead. Peer into the future and place a reminder in your Google Calendar or iCal to get fresh passport photos and make an appointment with the U.S. consulate (required if you're renewing your child's passport abroad).

In a hurry to renew? The State Department provides information HERE. And prepare to pay more.