compare time in Access

[wxdqz]

I've a problem comparing time from access to delete the entry

it looks like that

$verfallszeit= date("d.m.Y H:i:s");
$SQL_Exec_String = "DELETE FROM Tasks WHERE Stop <= '$verfallszeit'";

I don't see any error ???
The verfasllszeit i also testetdate ("d.m.y H:i:s"), date("Y-m-d H:i:s"), date("y-m-d H:i:s")

is there a mistake ??

Thanks