From 3f67dbe66f280881722dba02181d8f0b8bb670cf Mon Sep 17 00:00:00 2001
From: Rhodri Pugh <rod@owsy.com>
Date: Mon, 24 May 2021 19:39:33 +0100
Subject: [PATCH] add support for DateTimeImmutable

Adds support for DateTimeImmutable by using the shared DateTimeInterface
which both this and DateTime implement.
---
 src/Spout/Common/Helper/CellTypeHelper.php       | 2 +-
 tests/Spout/Common/Helper/CellTypeHelperTest.php | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Spout/Common/Helper/CellTypeHelper.php b/src/Spout/Common/Helper/CellTypeHelper.php
index 97d2e8d..c1609c3 100644
--- a/src/Spout/Common/Helper/CellTypeHelper.php
+++ b/src/Spout/Common/Helper/CellTypeHelper.php
@@ -61,7 +61,7 @@ class CellTypeHelper
     public static function isDateTimeOrDateInterval($value)
     {
         return (
-            $value instanceof \DateTime ||
+            $value instanceof \DateTimeInterface ||
             $value instanceof \DateInterval
         );
     }
diff --git a/tests/Spout/Common/Helper/CellTypeHelperTest.php b/tests/Spout/Common/Helper/CellTypeHelperTest.php
index 0797399..20e5247 100644
--- a/tests/Spout/Common/Helper/CellTypeHelperTest.php
+++ b/tests/Spout/Common/Helper/CellTypeHelperTest.php
@@ -90,6 +90,7 @@ class CellTypeHelperTest extends TestCase
     public function testIsDateOrInterval()
     {
         $this->assertTrue(CellTypeHelper::isDateTimeOrDateInterval(new \DateTime()));
+        $this->assertTrue(CellTypeHelper::isDateTimeOrDateInterval(new \DateTimeImmutable()));
         $this->assertTrue(CellTypeHelper::isDateTimeOrDateInterval(new \DateInterval('P1D')));
 
         $this->assertFalse(CellTypeHelper::isDateTimeOrDateInterval(true));