Note: At the 12 minute and 15 second mark of the following Form Exercise SOLUTION video, there are two typos. Where the second and third select menus say "month=..." it should actually say "name=...", like the first select menu. So the code on lines 46 and 53 should be as follows:

<select name="day">
and..
<select name="year">

Meanwhile, some of you may have found the minlength and maxlength attributes to use for the input validation. This method has less browser support than the pattern attribute.