I discovered a bug in Zend_Date
when setting a time that crosses the DST change.
Here's code that illustrates the problem:
date_default_timezone_set('America/New_York');
echo '<pre>';
// DST BEGINS '2012-03-11 02:00:00' - "Spring Forward"
$a = new Zend_Date('2012-03-11 00:00:00', 'yyyy-MM-dd HH:mm:ss');
$a->setTime('04:00:00', 'HH:mm:ss');
echo $a->toString('yyyy-MM-dd HH:mm:ss', 'iso')
. ' // expected: 2012-03-11 04:00:00' . PHP_EOL;
$b = new Zend_Date('2012-03-11 04:00:00', 'yyyy-MM-dd HH:mm:ss');
$b->setTime('00:00:00', 'HH:mm:ss');
echo $b->toString('yyyy-MM-dd HH:mm:ss', 'iso')
. ' // expected: 2012-03-11 00:00:00' . PHP_EOL;
// DST ENDS '2012-11-04 02:00:00' - "Fall Back"
$c = new Zend_Date('2012-11-04 00:00:00', 'yyyy-MM-dd HH:mm:ss');
$c->setTime('04:00:00', 'HH:mm:ss');
echo $c->toString('yyyy-MM-dd HH:mm:ss', 'iso')
. ' // expected: 2012-11-06 04:00:00' . PHP_EOL;
$d = new Zend_Date('2012-11-04 04:00:00', 'yyyy-MM-dd HH:mm:ss');
$d->setTime('00:00:00', 'HH:mm:ss');
echo $d->toString('yyyy-MM-dd HH:mm:ss', 'iso')
. ' // expected: 2012-11-06 00:00:00' . PHP_EOL;
echo '</pre>';
Ouputs:
2012-03-11 05:00:00 // expected: 2012-03-11 04:00:00
2012-03-10 23:00:00 // expected: 2012-03-11 00:00:00
2012-11-04 03:00:00 // expected: 2012-11-06 04:00:00
2012-11-04 01:00:00 // expected: 2012-11-06 00:00:00
I need to work around this bug, and I am stumped.
SOLUTION
Based on the answer from nerdzila, and research on a bug introduced by his solution, I now have this in my sub-classed Zend_Date
:
/**
* Call the function twice to work around the DST bug
* http://zendframework.com/issues/browse/ZF-10584
* https://stackoverflow.com/questions/7181702/work-around-for-zend-date-dst-bug
* https://stackoverflow.com/questions/8593660/zend-date-dst-bug-test-whether-a-date-is-a-time-change-date
* TODO: remove this once the bug is fixed
*
* @param string|integer|array|Zend_Date $time Time to set
* @param string $format OPTIONAL Timeformat for parsing input
* @param string|Zend_Locale $locale OPTIONAL Locale for parsing input
* @return My_Date Provides fluid interface
* @throws Zend_Date_Exception
*/
public function setTime($time, $format = null, $locale = null)
{
// start time zone juggling so that localtime() returns the correct results
$tzOrig = date_default_timezone_get();
date_default_timezone_set($this->getTimezone());
// capture orignal info
$timeInfoOrg = localtime($this->getTimestamp(), true);
// set the time
parent::setTime($time, $format, $locale);
// if the dst has changed, perform workaround
$timeInfoNew = localtime($this->getTimestamp(), true);
if ((0 < $timeInfoOrg['tm_isdst']) != (0 < $timeInfoNew['tm_isdst'])) {
// set the time again
parent::setTime($time, $format, $locale);
// if the day changed, set it back
if ($timeInfoOrg['tm_yday'] != $timeInfoNew['tm_yday']) {
// localtime() year date is zero indexed, add one
$this->setDayOfYear($timeInfoOrg['tm_yday'] + 1);
}
}
// end time zone juggling
date_default_timezone_set($tzOrig);
// fluent
return $this;
}
I can simply remove it once the bug is fixed.
That's an unfortunate bug. I got around it by calling
setTime()
twice for each date:My results: