From 0a78abe0886be3530bb8354eeef56a4b00d4bd32 Mon Sep 17 00:00:00 2001
From: mscherer <dereuromark@web.de>
Date: Sat, 14 Mar 2026 18:46:05 +0100
Subject: [PATCH] Add time comparison methods to ChronosTime

Add isStartOfDay(), isEndOfDay(), isMidnight(), and isMidday() methods
to ChronosTime for checking if a time instance represents common
boundary times.

- isStartOfDay(): Checks if time is 00:00:00.000000
- isEndOfDay(): Checks if time is 23:59:59 (ignores microseconds)
- isMidnight(): Alias for isStartOfDay()
- isMidday(): Checks if time is 12:00:00.000000
---
 src/ChronosTime.php                | 48 ++++++++++++++++++++++++++++++
 tests/TestCase/ChronosTimeTest.php | 36 ++++++++++++++++++++++
 2 files changed, 84 insertions(+)

diff --git a/src/ChronosTime.php b/src/ChronosTime.php
index 7d65dd2..22600cd 100644
--- a/src/ChronosTime.php
+++ b/src/ChronosTime.php
@@ -460,6 +460,54 @@ public function between(ChronosTime $start, ChronosTime $end, bool $equals = tru
         return $this->greaterThan($start) && $this->lessThan($end);
     }
 
+    /**
+     * Returns whether time is start of day.
+     *
+     * @return bool
+     */
+    public function isStartOfDay(): bool
+    {
+        return $this->ticks === 0;
+    }
+
+    /**
+     * Returns whether time is end of day.
+     *
+     * Compares against 23:59:59, ignoring microseconds.
+     *
+     * @return bool
+     */
+    public function isEndOfDay(): bool
+    {
+        $endOfDayTicks = 23 * self::TICKS_PER_HOUR
+            + 59 * self::TICKS_PER_MINUTE
+            + 59 * self::TICKS_PER_SECOND;
+
+        $ticksWithoutMicroseconds = $this->ticks - $this->ticks % self::TICKS_PER_SECOND;
+
+        return $ticksWithoutMicroseconds === $endOfDayTicks;
+    }
+
+    /**
+     * Returns whether time is midnight.
+     *
+     * @return bool
+     */
+    public function isMidnight(): bool
+    {
+        return $this->isStartOfDay();
+    }
+
+    /**
+     * Returns whether time is midday.
+     *
+     * @return bool
+     */
+    public function isMidday(): bool
+    {
+        return $this->ticks === 12 * self::TICKS_PER_HOUR;
+    }
+
     /**
      * Returns an `DateTimeImmutable` instance set to this clock time.
      *
diff --git a/tests/TestCase/ChronosTimeTest.php b/tests/TestCase/ChronosTimeTest.php
index 92b6786..5dd3c00 100644
--- a/tests/TestCase/ChronosTimeTest.php
+++ b/tests/TestCase/ChronosTimeTest.php
@@ -269,6 +269,42 @@ public function testComparisons(): void
         $this->assertFalse($t3->between($t1, $t2));
     }
 
+    public function testIsStartOfDay(): void
+    {
+        $this->assertTrue(ChronosTime::parse('00:00:00')->isStartOfDay());
+        $this->assertTrue(ChronosTime::midnight()->isStartOfDay());
+        $this->assertFalse(ChronosTime::parse('00:00:00.000001')->isStartOfDay());
+        $this->assertFalse(ChronosTime::parse('00:00:01')->isStartOfDay());
+        $this->assertFalse(ChronosTime::noon()->isStartOfDay());
+    }
+
+    public function testIsEndOfDay(): void
+    {
+        $this->assertTrue(ChronosTime::parse('23:59:59')->isEndOfDay());
+        $this->assertTrue(ChronosTime::endOfDay()->isEndOfDay());
+        $this->assertTrue(ChronosTime::parse('23:59:59.999999')->isEndOfDay());
+        $this->assertFalse(ChronosTime::parse('23:59:58')->isEndOfDay());
+        $this->assertFalse(ChronosTime::midnight()->isEndOfDay());
+        $this->assertFalse(ChronosTime::noon()->isEndOfDay());
+    }
+
+    public function testIsMidnight(): void
+    {
+        $this->assertTrue(ChronosTime::midnight()->isMidnight());
+        $this->assertTrue(ChronosTime::parse('00:00:00')->isMidnight());
+        $this->assertFalse(ChronosTime::parse('00:00:00.000001')->isMidnight());
+        $this->assertFalse(ChronosTime::noon()->isMidnight());
+    }
+
+    public function testIsMidday(): void
+    {
+        $this->assertTrue(ChronosTime::noon()->isMidday());
+        $this->assertTrue(ChronosTime::parse('12:00:00')->isMidday());
+        $this->assertFalse(ChronosTime::parse('12:00:00.000001')->isMidday());
+        $this->assertFalse(ChronosTime::parse('12:00:01')->isMidday());
+        $this->assertFalse(ChronosTime::midnight()->isMidday());
+    }
+
     public function testToDateTimeImmutable(): void
     {
         $time = ChronosTime::parse('23:59:59.999999');