PHP模拟夏令时

Question

I have some code that handles dates and times. I think it's OK, but want to test that it works when the clocks go forwards for DST.

I can change the timezone using date_default_timezone_set('Europe/London');, and wondered if there is an easy to simulate being in DST without having to wait till the clocks change!

Answer 1

You don't provide details on what you want to test but I assume you have functions to do time-related stuff, e.g.:

function setExpiryTime(DateTime $start, $minutes){
}

The obvious test is to provide input parameters that will make your code cross DST boundaries. You can either find such information in your favourite search engine or run a simple PHP snippet:

<?php

$timezone = new DateTimeZone('Europe/London');
print_r( $timezone->getTransitions(mktime(0, 0, 0, 1, 1, date('Y')), mktime(0, 0, 0, 12, 31, date('Y'))) );

Array
(
    [0] => Array
        (
            [ts] => 1388530800
            [time] => 2013-12-31T23:00:00+0000
            [offset] => 0
            [isdst] => 
            [abbr] => GMT
        )

    [1] => Array
        (
            [ts] => 1396141200
            [time] => 2014-03-30T01:00:00+0000
            [offset] => 3600
            [isdst] => 1
            [abbr] => BST
        )

    [2] => Array
        (
            [ts] => 1414285200
            [time] => 2014-10-26T01:00:00+0000
            [offset] => 0
            [isdst] => 
            [abbr] => GMT
        )

)

Thus you can test:

setExpiryTime(new DateTime('2014-03-30T00:55:00+0000'), 10);
setExpiryTime(new DateTime('2014-10-26T00:55:00+0000'), 10);