diff --git a/tests/Moment/WeekdayTest.php b/tests/Moment/WeekdayTest.php
new file mode 100644
index 0000000..8d854f1
--- /dev/null
+++ b/tests/Moment/WeekdayTest.php
@@ -0,0 +1,93 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DigitalCraftsman\DateTimePrecision\Moment;
+
+use DigitalCraftsman\DateTimePrecision\Moment;
+use DigitalCraftsman\DateTimePrecision\Weekday;
+use PHPUnit\Framework\TestCase;
+
+/** @coversDefaultClass \DigitalCraftsman\DateTimePrecision\Moment */
+final class WeekdayTest extends TestCase
+{
+    /**
+     * @test
+     *
+     * @dataProvider dataProviderForTime
+     *
+     * @covers ::weekday
+     */
+    public function weekday_works(
+        Weekday $expectedResult,
+        Moment $dateTime,
+    ): void {
+        // -- Act & Assert
+        self::assertEquals($expectedResult, $dateTime->weekday());
+    }
+
+    /**
+     * @return array<string, array{
+     *   0: Weekday,
+     *   1: Moment,
+     * }>
+     */
+    public static function dataProviderForTime(): array
+    {
+        return [
+            'same weekday in UTC' => [
+                Weekday::SATURDAY,
+                Moment::fromString('2022-10-08 15:00:00'),
+            ],
+            'weekday adapted due to weekday zone difference' => [
+                Weekday::SATURDAY,
+                Moment::fromStringInTimeZone('2022-10-08 00:00:00', new \DateTimeZone('Europe/Berlin'))
+                    ->toTimeZone(new \DateTimeZone('Europe/Berlin')),
+            ],
+        ];
+    }
+
+    /**
+     * @test
+     *
+     * @dataProvider dataProviderForTimeInTimeZone
+     *
+     * @covers ::weekdayInTimeZone
+     */
+    public function weekday_in_weekday_zone_works(
+        Weekday $expectedResult,
+        Moment $dateTime,
+        \DateTimeZone $weekdayZone,
+    ): void {
+        // -- Act & Assert
+        self::assertEquals($expectedResult, $dateTime->weekdayInTimeZone($weekdayZone));
+    }
+
+    /**
+     * @return array<string, array{
+     *   0: Weekday,
+     *   1: Moment,
+     *   2: \DateTimeZone,
+     * }>
+     */
+    public static function dataProviderForTimeInTimeZone(): array
+    {
+        return [
+            'same weekday in UTC' => [
+                Weekday::SATURDAY,
+                Moment::fromString('2022-10-08 15:00:00'),
+                new \DateTimeZone('UTC'),
+            ],
+            'adapting weekday for two hours through timezone difference' => [
+                Weekday::SUNDAY,
+                Moment::fromString('2022-10-08 23:00:00'),
+                new \DateTimeZone('Europe/Berlin'),
+            ],
+            'same weekday when timezone was used for creation of datetime' => [
+                Weekday::SATURDAY,
+                Moment::fromStringInTimeZone('2022-10-08 15:00:00', new \DateTimeZone('Europe/Berlin')),
+                new \DateTimeZone('Europe/Berlin'),
+            ],
+        ];
+    }
+}