Summing two dates

nipo

Hi !

I have a litle problem.

I have on my form four field. In first I have a birthdays in format d-m-Y(12-03-1994). Second field calculatig age from birthday until now ,formated Y-m-d (29-04-10 for example), and have a code :

$start_date = '{yourtable___yourdate}';
if (!empty($start_date)) {
$now_date = new DateTime();
$start_date = new DateTime($start_date);
$since_start = $start_date->diff($now_date);
return $since_start->format('%y-%m-%d');
}
else {
return "no data";
}

and work fine .

PROBLEM IS : In third field have another age in format Y-m-d for example 13-05-16 , and want summ with second field. (29-04-10 + 13-05-16 = 42-09-26)

The summ of calculating 42-09-26 (Y-m-d) must be displayed in fourth field ,but how.😕

Weedpacket

Since adding two dates to get a third date is meaningless (at least, I can't think of what the third date could mean), there is no date/time library function to do the job.
You'll need to separate the individual parts as numbers yourself and add them yourself. And you wouldn't be able to make a date out of the results (well, you could, but it wouldn't be what you want).

nipo

Exactly that.I know that I need separate parts of date in Years,months and days and then adding it , but don't now how.I have in excel whole procedure,but impossible to me to somehow convert this in php.

Weedpacket

Well, you know how to get the year, the month, and the day, because you're doing that with your use of format(). So get them separately instead of all together.

NogDog

Possibly a job for DateTime::add(), assuming what you are adding is really a DateInterval?