mysql-function to count days between 2 dates excluding weekends

Question

I\'ve searched through many examples , good ones I got :

1. Count days between two dates, excluding weekends (MySQL only)

2. How to count date dif

Answer 1

UPDATED: If you just need a number of weekdays between two dates you can get it like this

CREATE FUNCTION TOTAL_WEEKDAYS(date1 DATE, date2 DATE)
RETURNS INT
RETURN ABS(DATEDIFF(date2, date1)) + 1
     - ABS(DATEDIFF(ADDDATE(date2, INTERVAL 1 - DAYOFWEEK(date2) DAY),
                    ADDDATE(date1, INTERVAL 1 - DAYOFWEEK(date1) DAY))) / 7 * 2
     - (DAYOFWEEK(IF(date1 < date2, date1, date2)) = 1)
     - (DAYOFWEEK(IF(date1 > date2, date1, date2)) = 7);

Note: The function will still work if you switch start date1 and end date2 dates.

Sample usage:

SELECT TOTAL_WEEKDAYS('2013-08-03', '2013-08-21') weekdays1,
       TOTAL_WEEKDAYS('2013-08-21', '2013-08-03') weekdays2;

Output:

| WEEKDAYS1 | WEEKDAYS2 |
-------------------------
|        13 |        13 |

Here is DBFiddle demo