Question

How to compare two dates in php and echo newer one?

My dates are in the following format: date("F j, Y, g:i a"); which give us August 12, 2011, 9:45 am.

My dates are as follow:

• date 1 $created
• date 2 $updated / if no updated have been made value is 0000-00-00 00:00:00

Any suggestion much appreciated.

Answer 1

$date1 = new DateTime("August 12, 2011, 9:45 am");
$date2 = new DateTime("August 12, 2011, 10:45 am");

$never_date = ($date1<$date2)?$date1:$date2;

echo $never_date->format("F j, Y, g:i a");

But note, that 0000-00-00 00:00:00 is a valid input for DateTime(), but will not work as expected. It will result in a -0001-11-30 00:00:00 (at least for PHP 5.3-VC9-nts on Win7 x64).

Update: I see two options for workarouning that 0000-00-00 00:00:00

• Allow nulls in that column in your DB and remove DEFAULT 0000-00-00 00:00:00.
• Check if $updated == '0000-00-00 00:00:00' and if so, just return $created:

• Check if $updated == '' (empty string) and if so return $created:

  if ($updated=='0000-00-00 00:00:00' || $updated=='')
      $never_date = $created;
  else
      $never_date = ($created<$updated)?$created:$updated;
  

I doubt that it’s right behaviour to show 0000-00-00 00:00:00 for a record that was never updated.