DateTimeZone::getTransitions()

timezone_transitions_get

(PHP 5 >= 5.2.0, PHP 7)

Returns all transitions for the timezone

说明

面向对象风格
publicDateTimeZone::getTransitions([int $timestamp_begin=PHP_INT_MIN[,int $timestamp_end=PHP_INT_MAX]]): array

过程化风格
timezone_transitions_get(DateTimeZone$object[,int $timestamp_begin=PHP_INT_MIN[,int $timestamp_end=PHP_INT_MAX]]): array

参数

$object

仅过程化风格：由timezone_open()返回的DateTimeZone对象。

$timestamp_begin

Begin timestamp.

$timestamp_end

End timestamp.

返回值

Returns numerically indexed array containing associative array with all transitions on success 或者在失败时返回FALSE.

更新日志

范例

Atimezone_transitions_get()example

<?php
$timezone = new DateTimeZone("Europe/London");
$transitions = $timezone->getTransitions();
print_r(array_slice($transitions, 0, 3));
?>

以上例程的输出类似于：

Array
(
    [0] => Array
        (
            [ts] => -9223372036854775808
            [time] => -292277022657-01-27T08:29:52+0000
            [offset] => 3600
            [isdst] => 1
            [abbr] => BST
        )
    [1] => Array
        (
            [ts] => -1691964000
            [time] => 1916-05-21T02:00:00+0000
            [offset] => 3600
            [isdst] => 1
            [abbr] => BST
        )
    [2] => Array
        (
            [ts] => -1680472800
            [time] => 1916-10-01T02:00:00+0000
            [offset] => 0
            [isdst] => 
            [abbr] => GMT
        )
)

Getting a timezone's offset and other data at a specified point in time (now, for example) using the new PHP5.3 parameters:
<?php
$theTime = time(); # specific date/time we're checking, in epoch seconds.
$tz = new DateTimeZone('America/Los_Angeles');
$transition = $tz->getTransitions($theTime,$theTime);
# only one array should be returned into $transition. Now get the data:
$offset = $transition[0]['offset'];
$abbr = $transition[0]['abbr'];
?>
Before PHP5.3, you'd have to loop through all of the Transitions up until the current point in time, which would be a very inefficient process.

This will work in PHP_VERSION < 5.3:
<?php
/** returns an array with two elements for spring and fall DST in a given year
 * works in PHP_VERSION < 5.3
 * 
 * @param integer $year
 * @param string $tz timezone
 * @return array
 **/
function getTransitionsForYear($year=null, $tz = null){
  if(!$year) $year=date("Y");
  if (!$tz) $tz = date_default_timezone_get();
  $timeZone = new DateTimeZone($tz);
  if (version_compare(PHP_VERSION, '5.3.0') >= 0) {
    $transitions = $timeZone->getTransitions(mktime(0, 0, 0, 2, 1, $year),mktime(0, 0, 0, 11, 31, $year));
    $index=1;
  } else {
    // since 1980 it is regular, the 29th element is 1980-04-06
      // change this in your timezone
      $first_regular_index=29;
      $first_regular_year=1980;
    $transitions = $timeZone->getTransitions();
    $index=($year-$first_regular_year)*2+$first_regular_index;
  }
  return array_slice($transitions, $index, 2);
}

Beware if you use getTransitions() without a minimum date, it can be slow...

This function will work in PHP < 5.3 :
/** returns an array with two elements for spring and fall DST in a given year
 *
 * @param integer $year
 * @param string $tz timezone
 * @return array
 **/
function getTransitionsForYear($year=null, $tz = null){
  if(!$year) $year=date("Y");
  
  if (!$tz) $tz = date_default_timezone_get();
  $timeZone = new DateTimeZone($tz);
  
  $transitions = $timeZone->getTransitions(mktime(0, 0, 0, 1, 1, $year));
  return array_slice($transitions, 1, 2);
}