PHP date() 为不同的用户返回不同的值

Question

I have a problem with some users receiving different dates in my project. The project runs under PHP 7.4 on IIS.

My Machine is in Vancouver and the users are in Brisbane Australia

I've isolated the issue to the code below:

$tzone = 'Australia/Brisbane';
$html  = '<br>Machine Date: '. date("Y-m-d H:i:s");
$html .= '<br>TimeZone: '. $tzone;
$tnow = new DateTime("now", new DateTimeZone($tzone));
$html .= '<br>Local Time: '.  $tnow->format('Y-m-d H:i:s') ;
echo $html;

Most users (over 100) receive the following (which is expected):

Machine Date: 2021-12-06 16:00:34
TimeZone: Australia/Brisbane
Local Time: 2021-12-07 10:00:34

However 2 get:

Machine Date: 2021-12-07 11:00:34
TimeZone: Australia/Brisbane
Local Time: 2021-12-07 10:00:34

I'm guessing this is something to do with the configuration of these users but havent been able to discover what it is. The users are set to their local timezones correctly and their clocks are set to the right time.

Answer 1

IF YOU'RE DEVELOPING ON LOCALHOST

There's Nothing Wrong With The Codes. The MACHINE DATE Displays the Users Computer Time and has nothing to do with the zone you specified.

The Local Time is affected by the zone you specified.

Machine Date: = Users Local Computers' Time (Not Affected By the zone you specified)

TimeZone: You need to specify what timezone should affect the last $html (Local Time)

Local Time: is influenced by the time zone you specified.

LIVE SERVER

On a live Server, the timezone is given by the server which you use.

Use PHP TimeZone

<?php

date_default_timezone_set('Africa/Lagos'); // set the default timezone here to use for machine date

$tzone = 'Australia/Brisbane';
$html  = '<br>Machine Date: '. date("Y-m-d H:i:s");
$html .= '<br>TimeZone: '. $tzone;
$tnow = new DateTime("now", new DateTimeZone($tzone));
$html .= '<br>Local Time: '.  $tnow->format('Y-m-d H:i:s') ;
echo $html;

?>