Index: wp-includes/date.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- wp-includes/date.php	(revision 61f5f38dcda9678570aadb7a74554dd9429320cf)
+++ wp-includes/date.php	(revision )
@@ -368,7 +368,7 @@
 
 		// Hours per day.
 		$min_max_checks['hour'] = array(
-			'min' => 1,
+			'min' => 0,
 			'max' => 23
 		);