Is age defined in the European Union?
<p>I feel <a href="https://travel.stackexchange.com/q/134011/4188">https://travel.stackexchange.com/q/134011/4188</a> should have been asked here so I am doing it. </p>

<blockquote>
  <p>To travel with a discounted Youth Pass, you must be aged from 12 up to and including 27 on the start date of the Eurail Pass.</p>
</blockquote>

<p>Is there a legal definition of what "age" is here? Some people in the linked Q&amp;A insist it is based on birthdays but I can't find anything to back that up. In other words, if I was born on Feb 31, how old I am on Feb 30 legally? (nonexisting days are deliberate to avoid the discussion on me doxxing myself)</p>

<p>In both common law countries and in civil law countries, words are given their plain meaning for legal purposes, unless there is an express definition to the contrary is provided. And, in Europe, the plain meaning is unambiguous and is what the plain language that you quote says. (The meaning would be ambiguous in the Korean language, or regarding a horse, in contrast.)</p>

<p>While there are times when there are age groupings that aren't the plain meaning (e.g. eligibility for youth sports league divisions, school enrollment), it isn't usually stated so plainly. For example, a sports team might have a U10 division which has a defined meaning, but is unlikely to say "for children under age 10" when it really means "for children under age 10 as of the first day of the season".</p>

european-union