DateTime::getTimezone doesn't return timezone name, but offset
<?php
$first = '2011-04-27';
$second = '2011-04-27 16:20:12';
$third = '2011-04-27 16:20:12+00';
$dt = new DateTime($first);
$dt->setTimeZone(new DateTimeZone($dt->getTimeZone()->getName()));
echo $dt->getTimezone()->getName().'<br />';
// OK
$dt = new DateTime($second);
$dt->setTimeZone(new DateTimeZone($dt->getTimeZone()->getName()));
echo $dt->getTimezone()->getName().'<br />';
// OK
$dt = new DateTime($third);
$dt->setTimeZone(new DateTimeZone($dt->getTimeZone()->getName()));
echo $dt->getTimezone()->getName().'<br />';
// Error
// ->getName() returns unexpectedly +00, which is not a name, but offset
DateTime extracts from the last string timezone name +00
, which is really not name, but offset and therefore cannot be set as timezone...
This behavior is causing troubles when (de)serializing DateTime object...
public function __sleep()
{
$this->fix = array($this->format('Y-m-d H:i:s'), $this->getTimezone()->getName());
return array('fix');
}
public function __wakeup()
{
$this->__construct($this->fix[0], new DateTimeZone($this->fix[1]));
开发者_C百科 unset($this->fix);
}
I know it would be better to get e.g. this string: 2011-04-27 16:20:12 UTC
, anyway as far as the metod is called getName()
, it shouldn't return +00
as a name, or should?
You have tried to create DateTime
object with timezone offset +00
, that's why it returned offset instead of valid timezone identifier and actually that means GMT+0000
. Using datetime string without offset you'll get PHP timezone identifier according to current timezone setting in DateTime object (or system).
With $third = '2011-04-27 16:20:12+00';
you have set +00:00
offset in DateTime
object instead of PHP identifier and DateTime
just returns that back with ->getName()
method.
Fixed offset doesn't provide information about DST rules so it can't be used to get back PHP TimeZone identifier. Example: In my zone it's GMT+2
at the moment (active DST) but if I put it in datetime string, DateTime object can't know when my offset changes to +1
, simply, it's always GMT+0200... that's all.
Offset +00
in your case matches a lot of different timezone identifiers like Atlantic/Reykjavík
, Africa/Casablanca
, Africa/Nouakchott
, etc.
That's why getName() method returns time offset instead of timezone!
This is not official explanation, but that's it in short version.
Of course, 2011-04-27 16:20:12+00
is not valid datetime string.
When I run that code, PHP says it doesn't recognize that format (formats are defined here) so the output is as a result of an error. However, I was able to run it like so:
$third = '2011-04-27 16:20:12 GMT';
$dt = new DateTime($third);
$dt->setTimeZone(new DateTimeZone($dt->getTimeZone()->getName()));
echo $dt->getTimezone()->getName().'<br />';
I think you can just replace +00
with just GMT
.
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