Get user timezone string with Javascript / PHP?

Question

I'm trying to get the user's timezone as a string on singup. example:

$timezone = "Asia/Tel_Aviv";

While researching the issue, I got how to Get timezone offset with Javascript, but I'm still unclear about how can I translate the timezone offset to a timezone string in php, as shown above?

Or, which other method cas I use in Javascript / PHP for getting the timezone string for each user?

I'm really not sure how to approach this.

you can't really get the user's timezone, since PHP is a server sided language. you would need to first get it with javascript, then send it to your server — kennypu, Feb 24 '13 at 10:58
Agreed - you can't do it in PHP alone. Your server doesn't get that information as a header. — Nick Pickering, Feb 24 '13 at 11:05
An easy way to do it would be to have javascript set it in a cookie, and then you can grab the cookie in PHP. — Nick Pickering, Feb 24 '13 at 11:06

score 12 · Accepted Answer · edited Jul 20 '17 at 14:45

12

You can't do this in PHP alone.

You can use Javascript to set the value in a cookie, then use PHP to read the cookie on the next page (re)load.

Javascript:

var dateVar = new Date()
var offset = dateVar.getTimezoneOffset();
document.cookie = "offset="+offset;

PHP:

echo $_COOKIE['offset'];

Use this to convert the offset to the friendly timezone name in PHP. Javascript returns the offset in minutes, while this PHP function expects the input to be in seconds - so multiply by 60. The third parameter is a boolean value of whether or not you are in Daylight Savings Time. Read the manual and update the code to fit your needs.

echo timezone_name_from_abbr("", intval($_COOKIE['offset'])*60, 0);

http://php.net/manual/en/function.timezone-name-from-abbr.php

edited Jul 20 '17 at 14:45

Kalidass

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answered Feb 24 '13 at 11:07

Nick Pickering

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But as deceze wrote, that won't help me generate a solid timezone, or will it? Maybe insisting on timezone strings isn't important? – Roy Feb 24 '13 at 11:12
@Roy I think I got it this time. – Nick Pickering Feb 24 '13 at 11:24

score 3 · Answer 2 · answered Feb 24 '13 at 11:06

You cannot get the timezone name from an offset. That's because there are many timezones which have the same offset at any given time, so you can't pick one based on an offset. (If you do, this will bite you in the butt later when the timezone goes into or out of DST, changing the offset.
Your best bet is to do geolocation by IP address (google it, lots of material out there) as a best first guess and then give the user an option to choose his timezone himself.

score 2 · Answer 3 · answered Jan 11 '14 at 19:48

function tzone(){
    if(isset($_SESSION["tz"])){ $return = $_SESSION["tz"]; } else {
        $ip = $_SERVER["REMOTE_ADDR"];
        $getip = file_get_contents("http://freegeoip.net/json/$ip");
        $getip = json_decode($getip);
        $lat = $getip->latitude; $lng = $getip->longitude; $country = $getip->country_name;
        $getzone = file_get_contents("http://api.geonames.org/timezoneJSON?lat=$lat&lng=$lng&username=demo"); //you can change "demo" to your own username. its free service
        $getzone = json_decode($getzone);
        $zone = $getzone->timezoneId;
        $_SESSION["tz"] = $zone;
        $return = $_SESSION["tz"];
    }
    return $return;
}

Pradeep Kumar · Answer 4 · 2018-09-17T14:28:22.043

You need to follow answers of Nicholas Pickering and deceze♦ partially. Do not use PHP's timezone_name_from_abbr function(Ref).

Follow these steps to get UTC time of any timezone set in user system:

Javascript (client-side):

var dateVar = new Date();
var offset = dateVar.getTimezoneOffset();
//getTimezoneOffset - returns the timezone difference between UTC and Local Time
document.cookie = "offset="+offset;

Php (server-side):

public function convert_utc_time($date)
{
    $time_difference = isset($_COOKIE['offset'])?$_COOKIE['offset']:'';
    if($time_difference != ''){
        $time = strtotime($date);
        $time = $time + ($time_difference*60); //minutes * 60 seconds
        $date = date("Y-m-d H:i:s", $time);
    } //on failure of js, default timezone is set as UTC below
    return $date;
}
..
..
//in my function
$timezone = 'UTC';
$date = $this->convert_utc_time($post_date); //$post_date('Y-m-d H:i:s')
echo strtotime($date. ' '. $timezone)

Get user timezone string with Javascript / PHP?

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