Question

Basically I want to get remaining time to expire. I did it easily in php 5.3.x like below

$now = new DateTime();
$future_date =  new DateTime($enddate);
$interval = $future_date->diff($now,false); // ->diff will not work on 5.2.x
$interval->format("%d d, %h h, %i m");

How can I do the something in PHP : 5.2.x(5.2.17).

What I tried :

new DateTime(date('Y-m-d H:i:s', $now->format('U') - $future_date->format('U')));

Not providing expected result.

Answer 1

Because PHP < 5.3 doesn’t support the DateInterval class, DateTime::diff() (which is the right way to do this) is unavailable. You will need to do this manually for it to work in 5.2.x.

The math is actually quite simple:

// Get the difference between the two dates, in seconds
$diff = $future_date->format('U') - $now->format('U');

// Calculate the days component
$d = floor($diff / 86400);
$diff %= 86400;

// Calculate the hours component
$h = floor($diff / 3600);
$diff %= 3600;

// Calculate the minutes component
$m = floor($diff / 60);

// Calculate the seconds component
$s = $diff % 60;

// $d, $h, $m and $s now contain the values you want, so you can just build a
// string from them
$str = "$d d, $h h, $m m, $s s";

However with larger intervals this will introduce inaccuracies, because it does not take leap seconds into account. This means that you could end up a few seconds out – but since your original format string does not contain a seconds component, I doubt this will matter too much for what you are doing.

Note also that you need to subtract $now from $future_date, not the other way around, or the result will be negative.

See it working