stuck mysql find last working day in previous month - mysql

Question

I would like to ask you that i want to find last working day in previous month in MYSQL.
How to do that ?
this code find last day previous month as the following:
LAST_DAY(Now()- INTERVAL 1 MONTH)
Result that i need as below:
Current Month= 2013-07-01====> Results should be 2013-06-28
Current Month= 2013-06-06====> Results should be 2013-05-31
How to find last working day in previous month ?
Regards

Answer 1

Here’s an example of what I thought of:
LAST_DAY(CURDATE() - INTERVAL 1 MONTH) -
INTERVAL (CASE WEEKDAY(LAST_DAY(CURDATE() - INTERVAL 1 MONTH))
WHEN 5 THEN 1
WHEN 6 THEN 2
ELSE 0 END) DAY

Answer 2

Try something like:
SET #lastworkingday = DATE_SUB(CURDATE(), INTERVAL DAYOFMONTH(CURDATE()) DAY);
// If saturday, take it back one day
IF DAYOFWEEK(#lastworkingday) = 7
THEN #lastworkingday := DATE_SUB(#lastworkingday, INTERVAL 1 DAY);
// If sunday, take it back two days
ELSE IF DAYOFWEEK(#lastworkingday) = 1
THEN #lastworkingday := DATE_SUB(#lastworkingday, INTERVAL 2 DAY);

Answer 3

There may be a more elegant way of writing this (I'd be surprised if there wasn't), but Gumbo's solution might look like this...
Note I've used #dt for testing. You could just substitute CURDATE() in your script.
SET #dt = '2012-07-01'; -- Last day of the previous month (June 2012) was a Saturday
SELECT CASE DAYOFWEEK(LAST_DAY(#dt-INTERVAL 1 MONTH))
WHEN 1 THEN LAST_DAY(#dt-INTERVAL 1 MONTH)-INTERVAL 2 DAY
WHEN 7 THEN LAST_DAY(#dt-INTERVAL 1 MONTH)-INTERVAL 1 DAY
ELSE LAST_DAY(#dt-INTERVAL 1 MONTH)
END x;
+------------+
| x |
+------------+
| 2012-06-29 | -- Friday 29th
+------------+
SET #dt = '2012-08-01'; -- Last day of the previous month (July 2012) was a Tuesday
SELECT CASE DAYOFWEEK(LAST_DAY(#dt-INTERVAL 1 MONTH))
WHEN 1 THEN LAST_DAY(#dt-INTERVAL 1 MONTH)-INTERVAL 2 DAY
WHEN 7 THEN LAST_DAY(#dt-INTERVAL 1 MONTH)-INTERVAL 1 DAY
ELSE LAST_DAY(#dt-INTERVAL 1 MONTH)
END x;
+------------+
| x |
+------------+
| 2012-07-31 | -- Tuesday 31st
+------------+
SET #dt = '2012-10-01'; -- Last day of the previous month (September 2012) was a Sunday
SELECT CASE DAYOFWEEK(LAST_DAY(#dt-INTERVAL 1 MONTH))
WHEN 1 THEN LAST_DAY(#dt-INTERVAL 1 MONTH)-INTERVAL 2 DAY
WHEN 7 THEN LAST_DAY(#dt-INTERVAL 1 MONTH)-INTERVAL 1 DAY
ELSE LAST_DAY(#dt-INTERVAL 1 MONTH)
END x;
+------------+
| x |
+------------+
| 2012-09-28 | -- Friday 28th
+------------+
Another way is to build a calendar table of all dates. Ignoring public holidays, the first and last working days of the month then are simply the min and max weekdays of the month.
Although, there is an argument that goes 'so why not just figure this bit out in your application code'!

Answer 4

To get last working date you have to follow following steps :
1. first of all get last date of last month .
2.check whether it is working day or not by weekday function . if it is sunday then subtract 2 from lastdate , if it is saturday then subtract 1 from lastdate otherwise do not change anything .
we can do this thing by case statement . check following query . it will really works :
SELECT
CASE WEEKDAY(LAST_DAY(CONCAT(YEAR(CURDATE()),'-' , MONTH(CURDATE())-1 ,'-' , 1)))
WHEN 6
THEN DATE_ADD(LAST_DAY(CONCAT(YEAR(CURDATE()),'-' , MONTH(CURDATE())-1 ,'-' , 1)),INTERVAL -2 DAY)
WHEN 5
THEN DATE_ADD(LAST_DAY(CONCAT(YEAR(CURDATE()),'-' , MONTH(CURDATE())-1 ,'-' , 1)),INTERVAL - 1 DAY)
ELSE
LAST_DAY(CONCAT(YEAR(CURDATE()),'-' , MONTH(CURDATE())-1 ,'-' , 1)) END;
http://sqlfiddle.com/#!2/d41d8/15940

Answer 5

if you subtract the day of current month then you will get the last day of previous month
(DATE_SUB(CURDATE(),INTERVAL DAYOFMONTH(CURDATE()) DAY))
For example, on the 12th of the month if we subtract 12 days,then well get the the last day of the previous month: