[Solved]-Highcharts / JavaScript month is incompatible with MySQL-Highcharts

HighCharts accepts datetime in to milliseconds

so first convert datetime string to milliseconds & then pass to HighCharts object.

Thanks a Lot @Waqar, the hint with the miliseconds brought me to this site link So I changed:

foreach ($dataDatum as &$value) {
$datetime1[] = date('y, n, j, G, i, s', strtotime($value));
}
unset($value); // Entferne die Referenz auf das letzte Element
foreach ($datetime1 as &$value) {
$datetime2[] = 'Date.UTC('.$value.')';
}
unset($value); // Entferne die Referenz auf das letzte Element

to

foreach ($dataDatum as &$value) {
$datetime1[] = strtotime($value);
}
unset($value); // Entferne die Referenz auf das letzte Element
foreach ($datetime1 as &$value) {
$datetime2[] = $value * 1000;
}
unset($value); // Entferne die Referenz auf das letzte Element

And this works totaly fine for me!