Number of days between two dates

Get Number of Days between two difference dates

<?php
// Set the default timezone to US/Eastern
date_default_timezone_set('US/Eastern');

// Will return the number of days between the two dates passed in
function count_days($a, $b) {
// First we need to break these dates into their constituent parts:
$a_parts = getdate($a);
$b_parts = getdate($b);

// Now recreate these timestamps, based upon noon on each day
// The specific time doesn't matter but it must be the same each day
$a_new = mktime(12, 0, 0, $a_dt['mon'], $a_dt['mday'], $a_dt['year']);
$b_new = mktime(12, 0, 0, $b_dt['mon'], $b_dt['mday'], $b_dt['year']);

// Subtract these two numbers and divide by the number of seconds in a
// day. Round the result since crossing over a daylight savings time
// barrier will cause this time to be off by an hour or two.
return round(abs($a_new - $b_new) / 86400);
}

// Prepare a few dates
$date1 = strtotime('12/3/1973 8:13am');
$date2 = strtotime('1/15/1974 10:15pm');
$date3 = strtotime('2/14/2005 1:32pm');

// Calculate the differences, they should be 43 & 11353
echo "<p>There are ", count_days($date1, $date2), " days.</p>";
echo "<p>There are ", count_days($date2, $date3), " days.</p>";
?>