make DateCaster tests timezone-agnostic

Author: xabbuh

Caster/DateCaster.php

@@ -92,7 +92,7 @@ public static function castPeriod(\DatePeriod $p, array $a, Stub $stub, $isNeste
         if (\PHP_VERSION_ID >= 70107) { // see https://bugs.php.net/74639
             foreach (clone $p as $i => $d) {
                 if (self::PERIOD_LIMIT === $i) {
-                    $now = new \DateTimeImmutable();
+                    $now = new \DateTimeImmutable('now', new \DateTimeZone('UTC'));
                     $dates[] = sprintf('%s more', ($end = $p->getEndDate())
                         ? ceil(($end->format('U.u') - $d->format('U.u')) / ((int) $now->add($p->getDateInterval())->format('U.u') - (int) $now->format('U.u')))
                         : $p->recurrences - $i

Tests/Caster/DateCasterTest.php

@@ -353,7 +353,7 @@ public function testDumpPeriod($start, $interval, $end, $options, $expected)
      */
     public function testCastPeriod($start, $interval, $end, $options, $xPeriod, $xDates)
     {
-        $p = new \DatePeriod(new \DateTime($start), new \DateInterval($interval), \is_int($end) ? $end : new \DateTime($end), $options);
+        $p = new \DatePeriod(new \DateTime($start, new \DateTimeZone('UTC')), new \DateInterval($interval), \is_int($end) ? $end : new \DateTime($end, new \DateTimeZone('UTC')), $options);
         $stub = new Stub();
 
         $cast = DateCaster::castPeriod($p, [], $stub, false, 0);