Cron/OneOff: Always use default time zone

src/Cron.php

@@ -5,6 +5,7 @@
 use Cron\CronExpression;
 use DateTime;
 use DateTimeInterface;
+use DateTimeZone;
 use InvalidArgumentException;
 use ipl\Scheduler\Contract\Frequency;
 
@@ -98,6 +99,7 @@ public function getExpression(): string
     public function startAt(DateTimeInterface $start): self
     {
         $this->start = clone $start;
+        $this->start->setTimezone(new DateTimeZone(date_default_timezone_get()));
 
         return $this;
     }
@@ -112,6 +114,7 @@ public function startAt(DateTimeInterface $start): self
     public function endAt(DateTimeInterface $end): Frequency
     {
         $this->end = clone $end;
+        $this->end->setTimezone(new DateTimeZone(date_default_timezone_get()));
 
         return $this;
     }

src/OneOff.php

@@ -4,17 +4,18 @@
 
 use DateTime;
 use DateTimeInterface;
-use InvalidArgumentException;
+use DateTimeZone;
 use ipl\Scheduler\Contract\Frequency;
 
 class OneOff implements Frequency
 {
-    /** @var DateTime Start time of this frequency */
+    /** @var DateTimeInterface Start time of this frequency */
     protected $dateTime;
 
-    public function __construct(DateTime $dateTime)
+    public function __construct(DateTimeInterface $dateTime)
     {
         $this->dateTime = clone $dateTime;
+        $this->dateTime->setTimezone(new DateTimeZone(date_default_timezone_get()));
     }
 
     public function isDue(DateTimeInterface $dateTime): bool

tests/CronTest.php

@@ -3,6 +3,7 @@
 namespace ipl\Tests\Scheduler;
 
 use DateTime;
+use DateTimeZone;
 use InvalidArgumentException;
 use ipl\Scheduler\Contract\Frequency;
 use ipl\Scheduler\Cron;
@@ -132,4 +133,37 @@ public function testJsonSerializeAndDeserialize()
         $this->assertEquals($start, $fromJson->getStart());
         $this->assertEquals($end, $fromJson->getEnd());
     }
+
+    public function testSerializeAndDeserializeHandleTimezonesCorrectly()
+    {
+        $oldTz = date_default_timezone_get();
+        date_default_timezone_set('Europe/Berlin');
+
+        try {
+            $start = new DateTime('01-06-2023T12:00:00', new DateTimeZone('America/New_York'));
+            $end = new DateTime('01-06-2024T07:00:00', new DateTimeZone('America/New_York'));
+
+            $cron = Cron::fromJson(
+                json_encode(
+                    (new Cron('@minutely'))
+                        ->startAt($start)
+                        ->endAt($end)
+                )
+            );
+
+            $this->assertEquals(
+                new DateTime('2023-06-01T18:00:00'),
+                $cron->getStart(),
+                'Cron::jsonSerialize() does not restore the start date with a time zone correctly'
+            );
+
+            $this->assertEquals(
+                new DateTime('2024-06-01T13:00:00'),
+                $cron->getEnd(),
+                'Cron::jsonSerialize() does not restore the end date with a time zone correctly'
+            );
+        } finally {
+            date_default_timezone_set($oldTz);
+        }
+    }
 }

tests/OneOffTest.php

@@ -3,7 +3,7 @@
 namespace ipl\Tests\Scheduler;
 
 use DateTime;
-use ipl\Scheduler\Contract\Frequency;
+use DateTimeZone;
 use ipl\Scheduler\OneOff;
 use PHPUnit\Framework\TestCase;
 
@@ -45,4 +45,29 @@ public function testJsonSerialize()
         $this->assertEquals($oneOff, $fromJson);
         $this->assertEquals($now, $fromJson->getStart());
     }
+
+    public function testSerializeAndDeserializeHandleTimezonesCorrectly()
+    {
+        $oldTz = date_default_timezone_get();
+        date_default_timezone_set('Europe/Berlin');
+
+        try {
+            $dateTime = new DateTime('01-06-2023T12:00:00', new DateTimeZone('America/New_York'));
+            $oneOff = OneOff::fromJson(json_encode(new OneOff($dateTime)));
+
+            $this->assertEquals(
+                new DateTime('2023-06-01T18:00:00'),
+                $oneOff->getStart(),
+                'OneOff::jsonSerialize() does not restore the start date with a time zone correctly'
+            );
+
+            $this->assertEquals(
+                new DateTime('2023-06-01T18:00:00'),
+                $oneOff->getEnd(),
+                'OneOff::jsonSerialize() does not restore the start/end date with a time zone correctly'
+            );
+        } finally {
+            date_default_timezone_set($oldTz);
+        }
+    }
 }