Description:
------------
PHP does not understand the notion of the TZ environment variable that IBM AIX uses, and defaults to the UTC time zone if an "incorrect" TZ value is encountered.

The format of the TZ variable, and the allowed values, can be found here:
http://publib.boulder.ibm.com/infocenter/pseries/index.jsp?topic=/com.ibm.aix.doc/files/aixfiles/environment.htm

If this could be considered for future releases, that would be a great relief. As many (all?) other software on the system seem to use the TZ correctly.


Otherwise, it would be great if the date.timezone setting would act as a fallback in case the TZ environment variable is considered invalid by PHP.

And, perhaps, that this is clarified in the documentation (http://se.php.net/manual/sv/function.date-default-timezone-get.php); i.e., that an incorrect TZ value directly yields a "UTC" timezone setting.

Reproduce code:
---------------
System environment configuration file /etc/environment contains:
TZ=NFT-1DFT,M3.5.0/02:00:00,M10.5.0/03:00:00

httpd.conf contains:
php_value date.timezone "Europe/Stockholm"

PHP script that displays the reverting-to-UTC behavior of PHP:

<?php
//  putenv('TZ=NFT-1DFT,M3.5.0/02:00:00,M10.5.0/03:00:00');

  echo 'TZ is: ' . getenv('TZ') . '<BR>';
  echo 'date.timezone is: ' . ini_get('date.timezone') . '<BR>';
  echo 'date_default_timezone_get() returns: ' . date_default_timezone_get() . '<BR>';
  echo 'Current time is: ' . strftime('%T') . '<BR>';

  echo '<BR>';

  echo 'Forcing the correct timezone (' . ini_get('date.timezone') . ')...<BR>';
  date_default_timezone_set(ini_get('date.timezone'));
  echo 'Correct current time is: ' . strftime('%T') . '<BR>';
?>


Expected result:
----------------
That the timezone is picked up and understood by PHP. This would equal the "Europe/Stockholm" timezone setting. That is:

TZ is: NFT-1DFT,M3.5.0/02:00:00,M10.5.0/03:00:00
date.timezone is: Europe/Stockholm
date_default_timezone_get() returns: Europe/Stockholm
Current time is: 19:20:10

Forcing the correct timezone (Europe/Stockholm)...
Correct current time is: 19:20:10

Actual result:
--------------
TZ is: NFT-1DFT,M3.5.0/02:00:00,M10.5.0/03:00:00
date.timezone is: Europe/Stockholm
date_default_timezone_get() returns: UTC
Current time is: 18:20:10

Forcing the correct timezone (Europe/Stockholm)...
Correct current time is: 19:20:10