CREATE DEFINER=`root`@`%` FUNCTION `getworkdaydiff`(b date, a date) RETURNS int(11)
DETERMINISTIC
COMMENT `Get Working day difference for 2 dates`
BEGIN
DECLARE freedays int;
SET freedays = 0;

SET @x = DATEDIFF(b, a);
IF @x<0 THEN
SET @m = a;
SET a = b;
SET b = @m;
SET @m = -1;
ELSE
SET @m = 1;
END IF;
SET @x = abs(@x) + 1;
/* days in first week */
SET @w1 = WEEKDAY(a)+1;
SET @wx1 = 8-@w1;
IF @w1>5 THEN
SET @w1 = 0;
ELSE
SET @w1 = 6-@w1;
END IF;
/* days in last week */
SET @wx2 = WEEKDAY(b)+1;
SET @w2 = @wx2;
IF @w2>5 THEN
SET @w2 = 5;
END IF;
/* summary */
SET @weeks = (@x-@wx1-@wx2)/7;
SET @noweekends = (@weeks*5)+@w1+@w2;
SET @result = @noweekends-freedays;
RETURN @result*@m;
END