feat: add start and end of day

Author: innocenzi

packages/datetime/src/DateTime.php

@@ -8,6 +8,7 @@
 use IntlCalendar;
 use Tempest\Clock\Clock;
 use Tempest\Container\GenericContainer;
+use Tempest\DateTime\Exception\UnexpectedValueException;
 use Tempest\Support\Language\Locale;
 
 /**
@@ -506,6 +507,22 @@ public function withTime(int $hours, int $minutes, int $seconds = 0, int $nanose
         );
     }
 
+    /**
+     * Returns a new instance set to midnight of the same day.
+     */
+    public function startOfDay(): static
+    {
+        return $this->withTime(0, 0, 0, 0);
+    }
+
+    /**
+     * Returns a new instance set to the end of the day.
+     */
+    public function endOfDay(): static
+    {
+        return $this->withTime(23, 59, 59, 999999999);
+    }
+
     #[\Override]
     public function jsonSerialize(): array
     {

packages/datetime/tests/DateTimeTest.php

@@ -611,6 +611,28 @@ public function test_with_time(): void
         $this->assertSame(0, $new->getNanoseconds());
     }
 
+    public function test_start_of_day(): void
+    {
+        $date = DateTime::todayAt(14, 0);
+        $new = $date->startOfDay();
+
+        $this->assertSame(0, $new->getHours());
+        $this->assertSame(0, $new->getMinutes());
+        $this->assertSame(0, $new->getSeconds());
+        $this->assertSame(0, $new->getNanoseconds());
+    }
+
+    public function test_end_of_day(): void
+    {
+        $date = DateTime::todayAt(14, 0);
+        $new = $date->endOfDay();
+
+        $this->assertSame(23, $new->getHours());
+        $this->assertSame(59, $new->getMinutes());
+        $this->assertSame(59, $new->getSeconds());
+        $this->assertSame(999999999, $new->getNanoseconds());
+    }
+
     public function test_timezone_info(): void
     {
         $timeZone = Timezone::EUROPE_BRUSSELS;