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

my function to resolve issue

function diffMonth($from, $to) {

        $fromYear = date("Y", strtotime($from));
        $fromMonth = date("m", strtotime($from));
        $toYear = date("Y", strtotime($to));
        $toMonth = date("m", strtotime($to));
        if ($fromYear == $toYear) {
            return ($toMonth-$fromMonth)+1;
        } else {
            return (12-$fromMonth)+1+$toMonth;
        }

    }

Answer 2

Follow up on the answer of @deceze (I've upvoted on his answer). Month will still count as a whole even if the day of the first date didn't reached the day of the second date.

Here's my simple solution on including the day:

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

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

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

$day1 = date('d', $ts1); /* I'VE ADDED THE DAY VARIABLE OF DATE1 AND DATE2 */
$day2 = date('d', $ts2);

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

/* IF THE DAY2 IS LESS THAN DAY1, IT WILL LESSEN THE $diff VALUE BY ONE */

if($day2<$day1){ $diff=$diff-1; }

The logic is, if the day of the second date is less than the day of the first date, it will reduce the value of $diff variable by one.

Answer 3

$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);

If Month switched from Jan to Feb above code will return you the $diff = 1 But if you want to consider next month only after 30 days then add below lines of code along with above.

$day1 = date('d', $ts1);
$day2 = date('d', $ts2);

if($day2 < $day1){ $diff = $diff - 1; }

Answer 4

This is a simple method I wrote in my class to count the number of months involved into two given dates :

public function nb_mois($date1, $date2)
{
    $begin = new DateTime( $date1 );
    $end = new DateTime( $date2 );
    $end = $end->modify( '+1 month' );

    $interval = DateInterval::createFromDateString('1 month');

    $period = new DatePeriod($begin, $interval, $end);
    $counter = 0;
    foreach($period as $dt) {
        $counter++;
    }

    return $counter;
}

Answer 5

Here is my solution. It's only checks years and monthes of dates. So, if one date is '31.10.15' and other is '02.11.15' it returns 1 month.

function get_interval_in_month($from, $to) {
    $month_in_year = 12;
    $date_from = getdate(strtotime($from));
    $date_to = getdate(strtotime($to));
    return ($date_to['year'] - $date_from['year']) * $month_in_year -
        ($month_in_year - $date_to['mon']) +
        ($month_in_year - $date_from['mon']);
}

Answer 6

To calculate the number of CALENDAR MONTHS (as also asked here) between two dates, I usually end up doing something like this. I convert the two dates to strings like "2020-05" and "1994-05", then get their respective result from the below function, then run a subtraction of those results.

/**
 * Will return number of months. For 2020 April, that will be the result of (2020*12+4) = 24244
 * 2020-12 = 24240 + 12 = 24252
 * 2021-01 = 24252 + 01 = 24253
 * @param string $year_month Should be "year-month", like "2020-04" etc.
 */
static private function calculate_month_total($year_month)
{
    $parts = explode('-', $year_month);
    $year = (int)$parts[0];
    $month = (int)$parts[1];
    return $year * 12 + $month;
}