Have you ever heard about the Six Month Rule when it comes to passports? We all know how important it is to have one when you want to travel to another country. They have expiration dates just like credit cards or driver's license. Unlike these two examples, when it comes to a passport, you run a big risk if you try to use it to enter a foreign country on March 28th, when your passport expires on March 29th.
Many European countries require visitor's passports to continue to be valid for another 90 days and even as much as 6 months after your arrival date to their country.
It wouldn't feel too good to land in a country and find that one of you can't enter. I'm sure that would ruin any vacation plans.