Is it possible to change the system date for php (only) - php

Question

Is it possible to change the system date for php (only).
I want this for debugging/testing purpose.
//Test 1 (2010-01-01)
$datetime = new DateTime(); //(2010-01-01)
//Test 2 (2010-02-01)
$datetime = new DateTime(); //(2010-02-01)
I can't really change the real system clock, because other developers are working on the same system (well I could but still).
I'm just hoping this is possible, or that someone knows a nice trick.
When I print the phpinfo(); I see the following line:
Timezone Database internal
Maybe it's changeable to something like "manual" and ad a timezone with +120
Thanks!

Answer 1

This sounds like an encapsulation issue -- why not search for all mentions of date() or time() and replace them with $site->getDisplayedDate(), or something else appropriate to your code?
I feel your pain, but I don't think there's any way to do this. Think about it this way... how would you feel if, in some unrelated code, you called time() and it gave you some date 3 weeks in the future?
You can change only timezone (and ofcourse only couple hours forward / backward; and not whole day forward), but thats not correct solution...

Answer 2

You could create your own DateTime class that extends the default DateTime and hence change the behaviour:
<?php
class CustomDateTimeVariables {
public static $date = 'now';
}
class CustomDateTime extends DateTime {
public function __construct($time = null, DateTimeZone $timezone = null) {
if ($time === null) {
$time = CustomDateTimeVariables::$date;
}
if ($timezone !== null) {
parent::__construct($time, $timezone);
} else {
parent::__construct($time);
}
}
}
CustomDateTimeVariables::$date = '2010-01-01';
$datetime1 = new CustomDateTime();
CustomDateTimeVariables::$date = '2010-01-02';
$datetime2 = new CustomDateTime();
var_dump($datetime1->Format('Y-m-d H:i:s')); //"2010-01-01 00:00:00"
var_dump($datetime2->Format('Y-m-d H:i:s')); //"2010-01-02 00:00:00"
?>
DEMO
This way you can also set the default time very easily (check CustomDateTimeVariables):
<?php
class CustomDateTimeVariables {
public static $date = 'now +120 hours';
}
class CustomDateTime extends DateTime {
public function __construct($time = null, DateTimeZone $timezone = null) {
if ($time === null) {
$time = CustomDateTimeVariables::$date;
}
if ($timezone !== null) {
parent::__construct($time, $timezone);
} else {
parent::__construct($time);
}
}
}
$datetime = new CustomDateTime();
var_dump($datetime->Format('Y-m-d H:i:s')); //"2013-10-29 13:37:39"
?>
..and when it goes live, you can simply change the default back to now.