将日期时间戳转换为相对时间时如何考虑GMT偏移

Question

I have timestamps in the following format: 2013-10-19 18:47:30

I am using this to convert to relative (x minutes, hours, days ago) time but it returns nothing for the most recent users, I assume because my system time is GMT -3 hours so it is interpreting it as a time in the future. If that is the case, how can I take the users GMT offset into account in the result?

$time = strtotime('2013-04-28 17:25:43');

echo 'event happened '.humanTiming($time).' ago';

function humanTiming ($time)
{

    $time = time() - $time; // to get the time since that moment

    $tokens = array (
        31536000 => 'year',
        2592000 => 'month',
        604800 => 'week',
        86400 => 'day',
        3600 => 'hour',
        60 => 'minute',
        1 => 'second'
    );

    foreach ($tokens as $unit => $text) {
        if ($time < $unit) continue;
        $numberOfUnits = floor($time / $unit);
        return $numberOfUnits.' '.$text.(($numberOfUnits>1)?'s':'');
    }

}

Answer 1

$eventTimeString = '2013-04-28 17:25:43';
$timezone = new DateTimeZone("Etc/GMT+3"); // Same as GMT-3, here you should use the users's timezone
$eventTime = new DateTime($eventTimeString , $timezone);

$diff = $eventTime->diff(new DateTime()); // Compare with 

The $diff variable now has number of seconds, months, days etc. since $eventTime

object(DateInterval)#4 (15) {
  ["y"]=>
  int(0)
  ["m"]=>
  int(7)
  ["d"]=>
  int(18)
  ["h"]=>
  int(17)
  ["i"]=>
  int(35)
  ["s"]=>
  int(38)
  ["weekday"]=>
  int(0)
  ["weekday_behavior"]=>
  int(0)
  ["first_last_day_of"]=>
  int(0)
  ["invert"]=>
  int(0)
  ["days"]=>
  int(232)
  ["special_type"]=>
  int(0)
  ["special_amount"]=>
  int(0)
  ["have_weekday_relative"]=>
  int(0)
  ["have_special_relative"]=>
  int(0)
}

Answer 2

Here is a rewrite of your method that will be more reliable/accurate:

function humanTiming($time){
    $timezone=new DateTimeZone("Australia/Melbourne"); // declare whatever your user's timezone is
    $time=new DateTime($time,$timezone);  // input your datetime
    $now=new DateTime("now",$timezone); // get current datetime
    if($time>$now){
        return "event hasn't happened yet";
    }elseif($time==$now){
        return "event is happening";
    }
    $diff=(array)$time->diff($now);  // get time between now and $time, cast as array

    $labels=array("y"=>"year","m"=>"month","d"=>"day","h"=>"hour","i"=>"minute","s"=>"second");
    $readable="";       // declare as empty string
    // filter the $diff array to only  the desired elements and loop
    foreach(array_intersect_key($diff,$labels) as $k=>$v){
        if($v>0){  // only add non-zero values to $readable
            $readable.=($readable!=""?", ":"")."$v {$labels[$k]}".($v>1?"s":"");
            //  use comma-space as glue | show value | show unit | pluralize when necessary
        }
    }
    return "event happened $readable ago";
}

echo humanTiming('2013-04-28 17:25:43');

// event happened 3 years, 10 months, 23 days, 8 hours, 33 minutes, 59 seconds ago