How do I find common dates/days in two date ranges

I want to find out common days/dates between two periods.

For example

period1: 25-10-2010 to 25-11-2010
period2: 10-11-2010 to 10-12-201开发者_如何转开发0

Here 15 days, 10-11 to 25-11 are common. How can I find it in PHP or Zend Framework.

Using NullUserException's suggested method

date_default_timezone_set('GMT');


$period1 = array('25-10-2010','25-11-2010');
$period2 = array('10-11-2010','10-12-2010');

$p1 = range(strtotime($period1[0]),strtotime($period1[1]),86400);
$p2 = range(strtotime($period2[0]),strtotime($period2[1]),86400);

$r = array_intersect($p1,$p2);

foreach($r as $date) {
 echo $date,' - ',date('d-M-Y H:i:s',$date),'<br />';
}

$nb_days = (strtotime($period1[1])-strtotime($period2[0])) / 86400

Should work.

See this SO answer for more info: https://stackoverflow.com/a/2970328/781153

And the corresponding code in PHP:

$period1 = ['25-10-2010', '25-11-2010'];
$period2 = ['10-11-2010', '10-12-2010'];
$dates = [
    'p1start' => new DateTime($period1[0]),
    'p1end' => new DateTime($period1[1]),
    'p2start' => new DateTime($period2[0]),
    'p2end' => new DateTime($period2[1])
];
$start = max($dates['p1start'], $dates['p2start']);
$end = min($dates['p1end'], $dates['p2end']);
$days = $start->diff($end);
var_dump($days);

Result:

object(DateInterval)[694]
[...]
  public 'invert' => int 0
  public 'days' => int 15
[...]

Note that the invert property may be 1, if there's no common days. A solution to get zero days when there's no overlap would be:

$commonDays = $start > $end ? 0 : $start->diff($end)->days;