php POST data to datetime - php

Question

I have an issue with my project. I want to create a .ics file with start and endtime defined by the user of the website. So I get a string for the start and the end year and for the start/end time as well. Now I want to create a DateTime object from this data. My problem is that I just get the timestamp from right now and not from the string made:
$eventStartDay = $_POST["eventStartDay"];
$eventStartMonth = $_POST["eventStartMonth"];
$eventStartYear = $_POST["eventStartYear"];
$eventStartHour = $_POST["eventStartHour"];
$eventStartMinute = $_POST["eventStartMinute"];
$eventStartSecond = $_POST["eventStartSecond"];
$startDateTime = $eventStartYear . "-" . $eventStartMonth . "-"
. $eventStartDay . "T" . $eventStartHour . ":"
. $eventStartMinute . ":" . $eventStartSecond . "+01:00";
$eventEndDay = $_POST["eventEndDay"];
$eventEndMonth = $_POST["eventEndMonth"];
$eventEndYear = $_POST["eventEndYear"];
$eventEndHour = $_POST["eventEndHour"];
$eventEndMinute = $_POST["eventEndMinute"];
$eventEndSecond = $_POST["eventStartSecond"];
$endDateTime = $eventEndYear . "-" . $eventEndMonth . "-"
. $eventEndDay . "T" . $eventEndHour . ":"
. $eventEndMinute . ":" . $eventEndSecond . "+01:00";
$cal = new SimpleICS();
$cal->addEvent(function($e) {
$e->startDate = new DateTime($startDateTime);
$e->endDate = new DateTime($endDateTime);
I checked the strings with var_dump() and I got the right answers. They should look like this: '2016-01-18T19:00:00+01:00'

Answer 1

Quoting the PHP manual on Anonymous functions:
Closures may also inherit variables from the parent scope. Any such variables must be passed to the use language construct.
So you need to close over the DateTime objects, e.g. you need to do
$cal->addEvent(function($e) use ($startDateTime, $endDateTime) {
$e->startDate = new DateTime($startDateTime);
$e->endDate = new DateTime($endDateTime);
}