在PHP中将时间和日期从一个时区转换为另一个时区

Basically what I need is an script that, when provided with a time and a timezone can return the time in another time zone.

My main issues are:

• Where to get the time offset from GMT from - is there a public database available for this?
• How to also take into consideration the daylight saving time (DST) differences as well.
• How to nicely wrap it all up inside an PHP class - or is there such a class already available?

<?php
$date = new DateTime('2000-01-01', new DateTimeZone('Pacific/Nauru'));
echo $date->format('Y-m-d H:i:sP') . "
";

$date->setTimezone(new DateTimeZone('Pacific/Chatham'));
echo $date->format('Y-m-d H:i:sP') . "
";
?>

The above examples will output:

2000-01-01 00:00:00+12:00
2000-01-01 01:45:00+13:45

found on DateTime Manual on php.net

EDIT: Like Pekka said: The DateTime class exists from 5.2 on and there you first have to find out which of the methods are realy implemented and which one only exist from 5.3 on.

Here i use this function for converting datetime into another timezone. For best result if you convert your datetime into utc timezone and then convert into required timezone then it is better result for it.

function ConvertTimezoneToAnotherTimezone($time, $currentTimezone, $timezoneRequired) {
    $dayLightFlag = false;
    $dayLgtSecCurrent = $dayLgtSecReq = 0;
    $system_timezone = date_default_timezone_get();
    $local_timezone = $currentTimezone;
    date_default_timezone_set($local_timezone);
    $local = date("Y-m-d H:i:s");
    /* Uncomment if daylight is required */
    //        $daylight_flag = date("I", strtotime($time));
    //        if ($daylight_flag == 1) {
    //            $dayLightFlag = true;
    //            $dayLgtSecCurrent = -3600;
    //        }
    date_default_timezone_set("GMT");
    $gmt = date("Y-m-d H:i:s ");

    $require_timezone = $timezoneRequired;
    date_default_timezone_set($require_timezone);
    $required = date("Y-m-d H:i:s ");
    /* Uncomment if daylight is required */
    //        $daylight_flag = date("I", strtotime($time));
    //        if ($daylight_flag == 1) {
    //            $dayLightFlag = true;
    //            $dayLgtSecReq = +3600;
    //        }

    date_default_timezone_set($system_timezone);

    $diff1 = (strtotime($gmt) - strtotime($local));
    $diff2 = (strtotime($required) - strtotime($gmt));

    $date = new DateTime($time);

    $date->modify("+$diff1 seconds");
    $date->modify("+$diff2 seconds");

    if ($dayLightFlag) {
        $final_diff = $dayLgtSecCurrent + $dayLgtSecReq;
        $date->modify("$final_diff seconds");
    }

    $timestamp = $date->format("Y-m-d H:i:s ");

    return $timestamp;
}

Thank You.

try this, it might help :)

function converToTz($time="",$toTz='',$fromTz='')
    {   
        // timezone by php friendly values
        $date = new DateTime($time, new DateTimeZone($fromTz));
        $date->setTimezone(new DateTimeZone($toTz));
        $time= $date->format('Y-m-d H:i:s');
        return $time;
    }

A bit description: The function takes 3 inputs, time to convert, timezone to convert to, current timezone and returns the output in the specified format.

I know its late. For anyone who would want simple function to convert utc to any local time zone

function UTCTimeToLocalTime($time, $tz = '', $FromDateFormat = 'Y-m-d H:i:s', $ToDateFormat = 'Y-m-d H:i:s')
{
if ($tz == '')
    $tz = date_default_timezone_get();

$utc_datetime = DateTime::createFromFormat($FromDateFormat, $time, new
    DateTimeZone('UTC'));
$local_datetime = $utc_datetime;

$local_datetime->setTimeZone(new DateTimeZone($tz));
return $local_datetime->format($ToDateFormat);
}

 echo UTCTimeToLocalTime('2015-07-01 13:30:00','America/Denver');