- date_diff: documentation ( source)
- date_create: documentation ( source)
- timezone_open: documentation ( source)
<?php
$year = 1997;
$day = 5;
$month = 12;
$tz = timezone_open('Europe/Berlin');
$age = date_diff(date_create("$year-$month-$day", $tz),
date_create('now', $tz));
if ($age->m > 1) {
echo 'Greater than 1';
} else {
echo 'Not greater than 1';
}