Description:
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The result of subtraction between result of strtotime("Monday 29 March 2010 06:00:00") and the result of strtotime("Monday 22 March 2010 06:00:00") is not a week, but instead is a week less 2,5 minutes...

Infact a week are 604800 seconds but the result of this subtraction is 601200.

I tried to subtract day per day in the interval and all subtractions are correct and results every time 86400 seconds.

Test script:
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<?php
error_reporting(E_ALL|E_STRICT);
date_default_timezone_set ('Europe/London');

$dates = array("Monday 15 March 2010 06:00:00", "Monday 22 March 2010 06:00:00",
  "Monday 29 March 2010 06:00:00", "Monday 05 April 2010 06:00:00", "Monday 12 April 2010 06:00:00", "Monday 19 April 2010 06:00:00");

var_dump($dates);
$datesInt = array();
foreach($dates as $date)
  $datesInt[] = strtotime($date);

$lastDate = $datesInt[0];
for($i = 1; $i < count($datesInt); $i++){
  $tmp = $datesInt[$i]-$lastDate;
  var_dump($tmp);
  $lastDate = $datesInt[$i];
}
?>

Expected result:
----------------
I think that all subtractions should be return 604800 seconds.

Actual result:
--------------
Actually one of subtractions return 601200 instead of 604800 seconds.