$sql = "SELECT Id, UserID, TimeAction, Command FROM users_checked WHERE UserId = 4 AND date(TimeAction) = '2016-12-05 '";

$q=$conn->query($sql);

$data = array();

    while($r=$q->fetchAll((PDO::FETCH_ASSOC))){
        $data[]=$r;
    }

$data = array(
        array(
            "Id" => "1",
            "UserID" => "1",
            "TimeAction" => "2016-11-29 08:00:00",
            "Command" => "Prijava"
        ),
        array(
            "ID" => "1",
            "USERID" => "1",
            "TimeAction" => "2016-11-29 10:05:14",
            "Command" => "Odjava"
        ),
        array(
            "Id" => "1",
            "UserID" => "1",
            "TimeAction" => "2016-11-29 12:22:14",
            "Command" => "PoslovniIzlazak"
        ),
        array(
            "ID" => "1",
            "USERID" => "1",
            "TimeAction" => "2016-11-29 13:32:14",
            "Command" => "Prijava"
        ),
        array(
            "ID" => "1",
            "USERID" => "1",
            "TimeAction" => "2016-11-29 16:00:00",
            "Command" => "Odjava"
        ),
    );