Javascript/PHP %Y-%m-%d %H:%M:%S adjust for the local computer time

Question

I have time data in mySQL in the format of %Y-%m-%d %H:%M:%S as UTC +0 format. And I want to display the time data adjusting for the local computer tha user is using.

For example: The data is 2012-05-29 15:00:00 Then the time should be shown to a user in East time 2012-05-29 11:00:00 (applying daylightsaving, UTC -4hour) and for the westcoast should displayed 2012-05-20 08:00:00 (URC -7hour)

Any scripts for converting this? either PHP or Javascript is good.Thanks!

You need JS for this, PHP runs on the server, and knows nothing about the client. — nico, May 29 '12 at 18:14
check this out: http://stackoverflow.com/questions/847185/convert-a-unix-timestamp-to-time-in-javascript — , May 29 '12 at 18:18
@clerksx: computer users are notorious for not setting things up properly, so there's no guarantee AT ALL that the user's system clock, let alone time zone settings, are correct. — Marc B, May 29 '12 at 18:26

Daren Schwenke · Answer 1 · 2012-05-29T18:25:31.717

Store all your dates internally using UTC and then for each user set:

if ( $_SESSION['user_timezone'] ) date_default_timezone_set($_SESSION['user_timezone']);

If you want to be brave and your users are internet based (as opposed to using VPN like most of mine) you can lookup their location using location services.

I store this per user and just let them pick.

Easy way to generate the timezone list to present to the user:

echo '<select id="userTimezone" onChange="some_ajax_function">
        <option value="">Please select your Timezone</option>';
foreach (DateTimeZone::listIdentifiers() as $value )
{
    if ( $_SESSION['user_timezone'] == $value )
    {
        $output .= '<option value="' . $value . '" selected="selected">' . htmlentities($value) . '</option>';
    }
    else
    {
        $output .= '<option value="' . $value . '">' . htmlentities($value) . '</option>';
    }
}
$output .= '</select>';

score 0 · Answer 2 · answered May 29 '12 at 18:24

0

Here is a quick example using PHP DateTime class.

$time = '2012-05-29 15:00:00';

$datetime = new DateTime($time, new DateTimeZone('UTC'));
$datetime->setTimezone(new DateTimeZone('America/Los_Angeles'));

echo $datetime->format('Y-m-d H:i:s'); // 2012-05-29 08:00:00

Date and Time Classes

answered May 29 '12 at 18:24

drew010

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What was the result? Are you using PHP 5.2 or greater? – drew010 May 29 '12 at 21:07

Javascript/PHP %Y-%m-%d %H:%M:%S adjust for the local computer time

2 Answers2