working on conversion of datetime to and from UTC

app/Utils/Traits/MakesTimezoneAdjustment.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace App\Utils\Traits;
+
+/**
+ * Class MakesTimezoneAdjustment
+ * @package App\Utils\Traits
+ */
+trait MakesTimezoneAdjustment
+{
+
+	public function createClientDate($utc_date , $timezone)
+	{
+
+		$userTimezone = new \DateTimeZone($timezone);
+		$gmtTimezone = new \DateTimeZone('GMT');
+		//$myDateTime = new \DateTime($utc_date, $gmtTimezone);
+		$offset = $userTimezone->getOffset($utc_date);
+		$myInterval = \DateInterval::createFromDateString((string)$offset . 'seconds');
+		$utc_date->add($myInterval);
+
+		return $utc_date;
+
+	}
+
+
+	public function createUtcDate($client_date, $timezone)
+	{
+
+		$userTimezone = new \DateTimeZone($timezone);
+		$gmtTimezone = new \DateTimeZone('GMT');
+		//$clientDateTime = new \DateTime($client_date, $userTimezone);
+		$offset = $userTimezone->getOffset($client_date);
+		$myInterval = \DateInterval::createFromDateString((string)$offset . 'seconds');
+		$client_date->add($myInterval);
+
+		return $client_date;
+	}
+
+}

tests/Unit/TimezoneTraitTest.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace Tests\Unit;
+
+use App\Utils\Traits\MakesTimezoneAdjustment;
+use Tests\TestCase;
+
+/**
+ * @test
+ * @covers  App\Utils\Traits\MakesTimezoneAdjustment
+ */
+class TimezoneTraitTest extends TestCase
+{
+
+	use MakesTimezoneAdjustment;
+
+
+	public function testConvertClientDateToUTCDateTimeTickOverNextDay()
+	{
+
+	    $date_src = '2007-04-19 22:59'; 
+	    $client_timezone = 'Europe/Amsterdam'; // +1 UTC
+    	$date_time = new \DateTime($date_src, new \DateTimeZone($client_timezone)); 
+
+    	$utc_date = $this->createClientDate($date_time, $client_timezone);
+
+    	$this->assertEquals($utc_date->format('Y-m-d'), '2007-04-19');
+	}
+
+	public function testConvertClientDateToUTCDateTimeSameDay()
+	{
+
+	    $date_src = '2007-04-19 21:59'; 
+	    $client_timezone = 'Europe/Amsterdam'; // +1 UTC
+    	$date_time = new \DateTime($date_src, new \DateTimeZone($client_timezone)); 
+
+    	$utc_date = $this->createUtcDate($date_time, $client_timezone);
+
+    	$this->assertEquals($utc_date->format('Y-m-d'), '2007-04-19');
+	}
+
+}