Server timezone, user timezone, user date format ...

[Andy_Kemp]

I dont know if its right way to do this. If you would do it in a different way pleas let me know.

 

Create unix timestamp with admin selected timezone else use server default timezone.

function create_timestamp($config) {
	
    $time_zone = ($config['site_time_zone'] === 'default') ? date_default_timezone_get() : $config['site_time_zone'];
    $date = date_create(NULL, timezone_open($time_zone));
    return date_timestamp_get($date);

}

Format unix timestamp to user selected timezone and date format else use default timezone and date format.

function format_timestamp($config, $ui, $timestamp) {
	
    $time_zone = (is_logged_in($ui) && $ui['time_zone'] !== 'default') ? $ui['time_zone'] : date_default_timezone_get();
    $date_format = (is_logged_in($ui) && $ui['date_format'] !== 'default') ? $ui['date_format'] : $config['default_date_format']; 
    $date = date_create('@'.$timestamp);
    date_timezone_set($date, timezone_open($time_zone));
    return date_format($date, $date_format);
	
}

Add interval to unix timestamp.

function add_interval_timestamp($config, $interval, $timestamp = NULL) {
	
    $timestamp = ($timestamp === NULL) ? NULL : '@'.$timestamp;
    $time_zone = ($config['site_time_zone'] === 'default') ? date_default_timezone_get() : $config['site_time_zone'];
    $date = date_create($timestamp, timezone_open($time_zone));
    date_add($date, date_interval_create_from_date_string($interval));
    return date_timestamp_get($date);
	
}

Substract interval from unix timestamp.

function sub_interval_timestamp($config, $interval, $timestamp = NULL) {
	
    $timestamp = ($timestamp === NULL) ? NULL : '@'.$timestamp;
    $time_zone = ($config['site_time_zone'] === 'default') ? date_default_timezone_get() : $config['site_time_zone'];
    $date = date_create($timestamp, timezone_open($time_zone));
    date_sub($date, date_interval_create_from_date_string($interval));
    return date_timestamp_get($date);
	
}

[requinix]

If you're looking for a critique, use the OOP methods instead of the procedural functions. Like

function format_timestamp($config, $ui, $timestamp) {
	
    $time_zone = (is_logged_in($ui) && $ui['time_zone'] !== 'default') ? $ui['time_zone'] : date_default_timezone_get();
    $date_format = (is_logged_in($ui) && $ui['date_format'] !== 'default') ? $ui['date_format'] : $config['default_date_format']; 
    $date = new DateTime('@'.$timestamp);
    $date->setTimezone(new DateTimeZone($time_zone));
    return $date->format($date_format);
	
}

Create unix timestamp with admin selected timezone else use server default timezone.

A Unix timestamp does not have timezones. It's the same number at the same time everywhere in the world. Your function does the same thing that a single call to time would.