Added missing date_default_timezone_set('UTC'); to the appropriate tests. A few now pass by not showing the timezone warning.

Author: philip

ext/date/tests/DateInterval_format.phpt

@@ -10,6 +10,7 @@ Daniel Convissor <danielc@php.net>
 <?php if (!method_exists('DateInterval', 'format')) die("skip: method doesn't exist"); ?>
 --FILE--
 <?php
+date_default_timezone_set('UTC');
 
 $date1 = new DateTime('2000-01-01 00:00:00');
 $date2 = new DateTime('2001-03-04 04:05:06');

ext/date/tests/bug48187.phpt

@@ -2,6 +2,8 @@
 Bug #48187 (DateTime::diff() corrupting microtime() result)
 --FILE--
 <?php
+date_default_timezone_set('UTC');
+
 // two arbitrary dates
 $date1 = new DateTime('2005-07-23');
 $date2 = new DateTime('2006-02-14');

ext/date/tests/bug51819.phpt

@@ -2,6 +2,8 @@
 Bug #51819 (Case discrepancy in timezone names cause Uncaught exception and fatal error)
 --FILE--
 <?php
+date_default_timezone_set('UTC');
+
 $aTzAbbr = timezone_abbreviations_list();
 
 $aTz = array();