Prepping everything for a PHP 8 release

src/Entity/Field/Datetime.php

@@ -34,4 +34,9 @@ class Datetime extends \DateTime implements EntityObjectInterface {
     {
         return strftime($format, $this->getTimestamp());
     }
+
+    public function ageAt(null|\DateTime $dateTime) : int
+    {
+        return (int) ( (int) ($dateTime ?: new DateTime())->format('Ymd') - (int) $this->format('Ymd') ) / 10000;
+    }
 }