Calculate the number of months between two dates in PHP?

Question

Without using PHP 5.3\'s date_diff function (I\'m using PHP 5.2.17), is there a simple and accurate way to do this? I am thinking of something like the code below, but I don

Answer 1

Like this:

$date1 = strtotime('2000-01-25');
$date2 = strtotime('2010-02-20');
$months = 0;

while (($date1 = strtotime('+1 MONTH', $date1)) <= $date2)
    $months++;

echo $months;

If you want to include days to, then use this:

$date1 = strtotime('2000-01-25');
$date2 = strtotime('2010-02-20');

$months = 0;

while (strtotime('+1 MONTH', $date1) < $date2) {
    $months++;
    $date1 = strtotime('+1 MONTH', $date1);
}

echo $months, ' month, ', ($date2 - $date1) / (60*60*24), ' days'; // 120 month, 26 days

Answer 2

Here is my solution. It checks both years and months of dates and find difference.

 $date1 = '2000-01-25';
 $date2 = '2010-02-20';
 $d1=new DateTime($date2); 
 $d2=new DateTime($date1);                                  
 $Months = $d2->diff($d1); 
 $howeverManyMonths = (($Months->y) * 12) + ($Months->m);

Answer 3

I recently needed to calculate age in months ranging from prenatal to 5 years old (60+ months).

Neither of the answers above worked for me. The first one I tried, which is basically a 1 liner for deceze's answer

$bdate = strtotime('2011-11-04'); 
$edate = strtotime('2011-12-03');
$age = ((date('Y',$edate) - date('Y',$bdate)) * 12) + (date('m',$edate) - date('m',$bdate));
. . .

This fails with the set dates, obviously the answer should be 0 as the month mark (2011-12-04) hasn't been reached yet, how ever the code returns 1.

The second method I tried, using Adam's code

$bdate = strtotime('2011-01-03'); 
$edate = strtotime('2011-02-03');
$age = 0;

while (strtotime('+1 MONTH', $bdate) < $edate) {
    $age++;
    $bdate = strtotime('+1 MONTH', $bdate);
}
. . .

This fails and says 0 months, when it should be 1.

What did work for me, is a little expansion of this code. What I used is the following:

$bdate = strtotime('2011-11-04');
$edate = strtotime('2012-01-04');
$age = 0;

if($edate < $bdate) {
    //prenatal
    $age = -1;
} else {
    //born, count months.
    while($bdate < $edate) {
        $age++;
        $bdate = strtotime('+1 MONTH', $bdate);
        if ($bdate > $edate) {
            $age--;
        }
    }
}

Answer 4

How about this:

$d1 = new DateTime("2009-09-01");
$d2 = new DateTime("2010-09-01");
$months = 0;

$d1->add(new \DateInterval('P1M'));
while ($d1 <= $d2){
    $months ++;
    $d1->add(new \DateInterval('P1M'));
}

print_r($months);

Answer 5

$date1 = '2000-01-25';
$date2 = '2010-02-20';

$ts1 = strtotime($date1);
$ts2 = strtotime($date2);

$year1 = date('Y', $ts1);
$year2 = date('Y', $ts2);

$month1 = date('m', $ts1);
$month2 = date('m', $ts2);

$diff = (($year2 - $year1) * 12) + ($month2 - $month1);

You may want to include the days somewhere too, depending on whether you mean whole months or not. Hope you get the idea though.

Answer 6

This is how I ended up solving it. I know I'm a little late but I hope this saves someone a lot time and lines of code.
I used DateInterval::format to display a human readable countdown clock in years, months, and days. Check https://www.php.net/manual/en/dateinterval.format.php for the format table to see your options on how to modify your return values. Should give you what you're looking for.

$origin = new DateTime('2020-10-01');
$target = new DateTime('2020-12-25');
$interval = $origin->diff($target);
echo $interval->format('%y years, %m month, %d days until Christmas.');

Outputs: 0 years, 2 month, 24 days