$strSQLdiff = "SELECT * FROM timeme WHERE status<>'0' AND (nexttime BETWEEN '23:50:00' AND '00:15:00')";
$objQuerydiff = $mysqli->query($strSQLdiff); echo mysqli_error();
$strSQLdiff = "SELECT * FROM timeme WHERE status<>'0' AND
(
(nexttime BETWEEN '23:50:00' AND '23:59:59')
OR
(nexttime BETWEEN '00:00:00' AND '00:15:00')
)
";