When using DateInterval('P3M') on 30th of November you get March instead of Ferbuary.
The DateInterval class
(PHP 5 >= 5.3.0)
Represents a date interval.
A date interval stores either a fixed amount of time (in years, months, days, hours etc) or a relative time string in the format that DateTime's constructor supports.
Number of years.
Number of months.
Number of days.
Number of hours.
Number of minutes.
Number of seconds.
Is 1 if the interval represents a negative time period and 0 otherwise. See DateInterval::format().
If the DateInterval object was created by DateTime::diff(), then this is the total number of days between the start and end dates. Otherwise, days will be
If you want to convert a Timespan given in Seconds into an DateInterval Object you could dot the following:
$dv = new DateInterval('PT'.$timespan.'S');
but wenn you look at the object, only the $dv->s property is set.
As stated in the documentation to DateInterval::format
The DateInterval::format() method does not recalculate carry over points in time strings nor in date segments. This is expected because it is not possible to overflow values like "32 days" which could be interpreted as anything from "1 month and 4 days" to "1 month and 1 day".
If you still want to calculate the seconds into hours / days / years, etc do the following:
$d1 = new DateTime();
$d2 = new DateTime();
$iv = $d2->diff($d1);
$iv is an DateInterval set with days, years, hours, seconds, etc ...
It would be nice that when converting a DateInterval to a string, the interval specification used to construct the object is returned (like "P2W").
I need this to serialize a DateInterval object in order to store it in a postgres DB.
I found the comment from p dot scheit to be very helpful, but I had to reverse d2 and d1 in the ->diff() call in order to get an incremental addition to a start time. Also NOTE the occurance of PHP passing objects by reference necessitates the CLONE of the DateTime object I pass to the function otherwise my object gets modified by the function call ::
$date_from = new \DateTime('2012-05-05 14:00:00');
$segments = 36;
$myDate = clone $date_from;
echo 'segment '.$x.' '.$this->getInterval($myDate,$x*$myResolution).'<br>';
segment 0 2012-05-05 14:10
segment 1 2012-05-05 14:20
segment 2 2012-05-05 14:30
segment 3 2012-05-05 14:40
segment 4 2012-05-05 14:50
segment 5 2012-05-05 15:00
segment 6 2012-05-05 15:10
$d1 = new \DateTime();
$d2 = new \DateTime();
$iv = $d1->diff($d2);
return $s->add($iv)->format('Y-m-d H:i');