PHP 8.0 > mktime update

8.0.0 	hour is no longer optional.
8.0.0 	minute, second, month, day and year are nullable now.

lib/i18n/sfI18N.class.php

@@ -271,6 +271,15 @@ public function getTimestampForCulture($dateTime, $culture = null)
     list($day, $month, $year) = $this->getDateForCulture($dateTime, null === $culture ? $this->culture : $culture);
     list($hour, $minute) = $this->getTimeForCulture($dateTime, null === $culture ? $this->culture : $culture);
 
+    // mktime behavior change with php8
+    // $hour become not nullable
+    if (!$hour) {
+      $hour = 0;
+    }
+    // Before 8.0, $minutes value to null, was casted as (int)0
+    if (!$minute) {
+      $minute = 0;
+    }
     return null === $day ? null : mktime($hour, $minute, 0, $month, $day, $year);
   }