diff --git a/ecrire/tests/Filtre/Date/DateIsoTest.php b/ecrire/tests/Filtre/Date/DateIsoTest.php
index c6ae9a8c9fd7e1c3bc2005b866fd8c866f2a1f5c..4783fbd4d948a7366b79286be31b28f9e64f92d6 100644
--- a/ecrire/tests/Filtre/Date/DateIsoTest.php
+++ b/ecrire/tests/Filtre/Date/DateIsoTest.php
@@ -13,14 +13,21 @@ use PHPUnit\Framework\TestCase;
 
 class DateIsoTest extends TestCase
 {
+	protected string $original_timezone;
+
 	public static function setUpBeforeClass(): void {
 		find_in_path('inc/filtres.php', '', true);
 	}
 
 	protected function setUp(): void {
+		$this->original_timezone = date_default_timezone_get();
 		date_default_timezone_set('UTC');
 	}
 
+	protected function tearDown(): void {
+		date_default_timezone_set($this->original_timezone);
+	}
+
 	#[DataProvider('providerDateIso')]
 	public function testDateIso($expected, ...$args): void {
 		$actual = date_iso(...$args);
@@ -28,7 +35,9 @@ class DateIsoTest extends TestCase
 	}
 
 	public static function providerDateIso(): array {
-		return [
+		$tz = date_default_timezone_get();
+		date_default_timezone_set('UTC');
+		$data = [
 			'01-01-2010' => [
 				0 => gmdate('Y-m-d\TH:i:s\Z', mktime(2, 5, 30, 1, 1, 2010)),
 				1 => '2010-01-01 02:05:30',
@@ -42,5 +51,7 @@ class DateIsoTest extends TestCase
 				1 => '2010-00-00 04:07:50',
 			],
 		];
+		date_default_timezone_set($tz);
+		return $data;
 	}
 }