putenv() vs. date_default_timezone_set()

[johnnyk]

What's the difference between:
putenv('TZ = timezone');
and
date_default_timezone_set('timezone');

[beezm]

Question:
[url=http://us3.php.net/putenv]putenv ( setting )[/url]
vs.
[url=http://us2.php.net/date_default_timezone_set]bool date_default_timezone_set ( timezone_identifier )[/url]
Difference ?

Well from what I have gathered from the php manual...

date_default_timezone_set() :: seems to be a new feature of php 5 and above.
putenv() :: function is used to set environment variables in php 3 and above.

Most answers about comparision of functions and other php built-in features can easily be found on php.net's manual for future reference.
http://www.php.net/