diff --git a/phpBB/phpbb/datetime.php b/phpBB/phpbb/datetime.php
index 4b799b6219..7384eeabbd 100644
--- a/phpBB/phpbb/datetime.php
+++ b/phpBB/phpbb/datetime.php
@@ -101,15 +101,15 @@ class datetime extends \DateTime
 				{
 					$day = false;
 
-					if ($timestamp > $midnight + 86400)
+					if ($timestamp >= $midnight + 86400)
 					{
 						$day = 'TOMORROW';
 					}
-					else if ($timestamp > $midnight)
+					else if ($timestamp >= $midnight)
 					{
 						$day = 'TODAY';
 					}
-					else if ($timestamp > $midnight - 86400)
+					else if ($timestamp >= $midnight - 86400)
 					{
 						$day = 'YESTERDAY';
 					}
diff --git a/tests/datetime/from_format_test.php b/tests/datetime/from_format_test.php
index d95bacdbce..2fe671bbec 100644
--- a/tests/datetime/from_format_test.php
+++ b/tests/datetime/from_format_test.php
@@ -58,7 +58,6 @@ class phpbb_datetime_from_format_test extends phpbb_test_case
 		$this->assertEquals($expected, $user->format_date($timestamp, $format, true));
 	}
 
-
 	public function relative_format_date_data()
 	{
 		// If the current time is too close to the testing time,
@@ -103,6 +102,20 @@ class phpbb_datetime_from_format_test extends phpbb_test_case
 				gmdate('Y-m-d', time() - 2 * 86400) . ' ' . $testing_time, false,
 				gmdate('Y-m-d', time() - 2 * 86400) . ' ' . $testing_time,
 			),
+
+			// Test edge cases: Yesterday 00:00, Today 00:00, Tomorrow 00:00
+			array(
+				gmdate('Y-m-d', strtotime('yesterday')) . ' 00:00', false,
+				'Yesterday 00:00',
+			),
+			array(
+				gmdate('Y-m-d', strtotime('today')) . ' 00:00', false,
+				'Today 00:00',
+			),
+			array(
+				gmdate('Y-m-d', strtotime('tomorrow')) . ' 00:00', false,
+				'Tomorrow 00:00',
+			),
 		);
 	}