SELECT
  MIN(TD_TIME_FORMAT(time,'yyyy-MM-dd','JST')) AS min_d,
  MAX(TD_TIME_FORMAT(time,'yyyy-MM-dd','JST')) AS max_d
FROM
(
  SELECT time
  FROM sales_slip
  WHERE TD_TIME_RANGE(time, '2006-05-01', '2006-06-01','JST')
)