Clean up namespace

Add european and meridional style date time tests

src/Validation/Validation.php

@@ -14,7 +14,6 @@
  */
 namespace Cake\Validation;
 
-use Cake\Chronos\Date;
 use Cake\I18n\Time;
 use Cake\Utility\Text;
 use DateTimeInterface;

tests/TestCase/Validation/ValidationTest.php

@@ -1596,9 +1596,11 @@ class ValidationTest extends TestCase
      */
     public function testDateTimeISO()
     {
-        $this->assertFalse(Validation::dateTime('2007/10/04T1:50'));
         $this->assertTrue(Validation::dateTime('2007/10/04T01:50'));
         $this->assertTrue(Validation::dateTime('2017/12/04T15:38'));
+        $this->assertTrue(Validation::dateTime('04.12.2017T15:38', ['dmy']));
+        $this->assertTrue(Validation::dateTime('24-02-2019T2:38am', ['dmy']));
+        $this->assertFalse(Validation::dateTime('2007/10/04T1:50'));
         $this->assertFalse(Validation::dateTime('2007/10/04T58:38'));
     }