Creating a business hours function

Question

I am new to oracle and I need to create a function that will take two datestamp and then tell me how many business hours are between those two dates.
Business hours are 6:00 Am to 6:00 pm Monday to Friday.
For example: if my startdate is 7/20/2010 8:00 am and end date us 7/2/2010 9:00 pm. The total work hour will be 10 hours not 13.
Another scenario:
start date: 7/20/2010 3:00 am and end time 7/20/2010 6:01 am. The total work hour is 1 min.
I am having serious difficulty with that.
Thanks
Amir

Answer 1

Hi, Amir,
user10356209 wrote:
Frank,
Thanks for your response. I really do not have a table that I need for this functiion. Right. The table is just for testing the function. Post a few rows to test.
CREATE OR REPLACE FUNCTION     business_hours
(      in_start_dt       IN          DATE     DEFAULT SYSDATE
,      in_end_dt       IN          DATE     DEFAULT     SYSDATE
RETURN     NUMBER
DETERMINISTIC
IS
--           **   b u s i n e s s _ h o u r s   **
--          business_hours returns the number of work houts (6 am through 6 pm,
--          Monday through Friday) between in_start_dt and in_end_dt.
--          If in_start_dt > in_end_dt, the results will be <= 0.
--          Holidays are not considered.
     d          NUMBER;                                -- Hours of either start_dt or end_dt after midnight
     end_dt          DATE    := GREATEST (in_start_dt, in_end_dt);  -- In case dates were in wrong order
     return_val     NUMBER;                                      -- Total number of working hours
     start_dt     DATE    := LEAST    (in_start_dt, in_end_dt);  -- In case dates were in wrong order
BEGIN
     WITH     all_days     AS
          SELECT     start_dt + LEVEL - 1     AS a_dt
          FROM     dual
          CONNECT BY LEVEL <= 1 + TRUNC (end_dt) - TRUNC (start_dt)
     SELECT     SUM (12)
     INTO     return_val
     FROM     all_days
     WHERE     TO_CHAR ( a_dt
               , 'Dy'
               , 'NLS_DATE_LANGUAGE = ''ENGLISH'''
               )       NOT IN ('Sat', 'Sun');
     -- Adjust hours from start_dt, if necessary
     IF  TO_CHAR ( start_dt
                  , 'Dy'
              , 'NLS_DATE_LANGUAGE = ''ENGLISH'''
              ) NOT IN ('Sat', 'Sun')
     THEN
          d := 24 * (start_dt - TRUNC (start_dt));
          IF  d >= 18
          THEN       -- Don't count start_dt itself
               return_val := return_val - 12;
          ELSIF  d > 6
          THEN    -- Don't count part of start_dt
               return_val := return_val - (d - 6);
          END IF;
     END IF;
     -- Adjust hours from end_dt, if necessary
     IF  TO_CHAR ( end_dt
                  , 'Dy'
              , 'NLS_DATE_LANGUAGE = ''ENGLISH'''
              ) NOT IN ('Sat', 'Sun')
     THEN
          d := 24 * (end_dt - TRUNC (end_dt));
          IF  d <= 6
          THEN       -- Don't count end_dt itself
               return_val := return_val - 12;
          ELSIF  d < 18
          THEN    -- Don't count part of end_dt
               return_val := return_val - (18 - d);
          END IF;
     END IF;
     IF  in_start_dt > in_end_dt
     THEN
          return_val := -return_val;
     END IF;
     RETURN     return_val;
END     business_hours
;Edited by: Frank Kulash on Jul 20, 2010 6:49 PM