Description:
------------
With the current 5.1RC2 snap setting the TZ environment variable to EST5 which is the correct setting for Indiana in the US doesn't work correctly.  Setting TZ to something like EST5EDT CST6CDT, PST8PDT etc does work.

Reproduce code:
---------------
<?
$date = date("h:i:s", time());
echo "Date: $date";
?>


Expected result:
----------------
I expect to see the correct time accounting for my time zone.

Actual result:
--------------
It was actually 09:52:28 AM and the date was printed as the following PM
Date: 02:52:28
PHP Notice:  date(): Timezone setting (date.timezone) or TZ environment variable contains an unknown timezone. in E:\tz.php on line 2