Changing date and time between timezones

Question

I have been trying to convert between timezones a given date and time.
Code speaks more than words, so here it is:

/**
 * Returns the date and time in the n         


        

Answer 1

OK, try this instead:

function changeDateTime($datetime, $input_tz, $output_tz) {

    // Return original string if in and out are the same
    if($input_tz == $output_tz) {
        return $datetime;
    }

    // Save current timezone setting and set to input timezone
    $original_tz = date_default_timezone_get();
    date_default_timezone_set($input_tz);

    // Get Unix timestamp based on input time zone
    $time = strtotime($datetime);

    // Start working in output timezone
    date_default_timezone_set($output_tz);

    // Calculate result
    $result = date('Y-m-d H:i:s', $time);

    // Set timezone correct again
    date_default_timezone_set($original_tz);

    // Return result
    return $result;

}

$out = changeDateTime("2012-08-10 11:33:33", 'Europe/London', 'Europe/Madrid');
var_dump($out);

Rather than messing about doing all that complicated maths, just let PHP do all the hard work for you ;-)

See it working

Answer 2

If your stumbling on this, it can be done cleaner now with the DateTime Object.

public function convertTZ($dateTimeString, $inputTZ, $outputTZ){
    $datetime = 
        \DateTime::createFromFormat('Y-m-d H:i:s', //input format - iso8601
        $dateTimeString, 
        new \DateTimeZone($inputTZ))
        ->setTimezone(new \DateTimeZone('$outputTZ'));

    //outputs a string, if you want the dateTime obj - remove ->format
    return $datetime->format('Y-m-d H:i:s'); //output format 

}