Peter Larsson Blog

Patron Saint of Lost Yaks

How to calculate the number of weekdays for any given period

Here http://weblogs.sqlteam.com/peterl/archive/2009/07/12/How-to-calculate-the-number-of-weekdays-in-a-month.aspx is a specialized version for a month, and here http://weblogs.sqlteam.com/peterl/archive/2009/07/12/How-to-calculate-number-of-weekdays-in-a-year.aspx is a specialized version for a year. This code below calculates the number of weekdays for any given period. Read more →

How to calculate the number of weekdays in a month

Here http://weblogs.sqlteam.com/peterl/archive/2009/07/12/How-to-calculate-the-number-of-weekdays-for-any-given.aspx you can find a specialized version that calculates number of weekdays for any given period. CREATEFUNCTION dbo.fnMonthWeekDays ( @Year SMALLINT, @Month TINYINT ) RETURNSTINYINT AS BEGIN RETURN ( SELECT 20 + SUM(1 - DATEDIFF(DAY, '17530101', dt) % 7 / 5) FROM ( SELECT DATEADD(MONTH, 12 * @Year - 22800 + @Month, -1) AS dt WHERE ISDATE(10000 * @Year + 100 * @Month + 31) = 1 UNION ALL SELECT DATEADD(MONTH, 12 * @Year - 22800 + @Month, -2) WHERE ISDATE(10000 * @Year + 100 * @Month + 30) = 1 UNION ALL SELECT CASE ISDATE(10000 * @Year + 100 * @Month + 29) WHEN 1 THEN DATEADD(MONTH, 12 * @Year - 22800 + @Month, -3) ELSE '18991231' END ) AS d WHERE @Year BETWEEN 1753 AND 9999 AND@Month BETWEEN 1 AND 12 ) END Legacy Comments Sowmya 2009-10-22 re: How to calculate the number of weekdays in a month Can u please explain the logic ? Read more →

How to calculate number of weekdays in a year

This function calculates the number of weeksdays in a year, and has error-checking for invalid years. It is also language independant. Here http://weblogs.sqlteam.com/peterl/archive/2009/07/12/How-to-calculate-the-number-of-weekdays-for-any-given.aspx you can find a specialized version that calculates number of weekdays for any given period. Read more →

Vacation

Finally, I am on vacation. I can't even remember when I had 4 week of contigous vacation last time! I wish the best to all of you, and see you soon again. Read more →

Microsoft MVP

Today it happened. I received the Microsoft MVP Award for my contributions to the Microsoft SQL Server community. I am very honored by the award and I will continue to work hard for the community to keep their trust in me. Read more →

Microsoft Connect - SSMS Debugger Issue

I've found an issue with the Debugger for SQL Server 2008 Management Studio a while ago. This is my way to ask you to endorse a fix https://connect.microsoft.com/SQLServer/feedback/ViewFeedback.aspx?FeedbackID=374183 Please let Microsoft know what you think about this suggestion. Read more →

Extended Get Nth Weekday of period

Recently I posted a function which returned the Nth weekday of a month, either from the beginning of month or from the end of month. Function is found here http://weblogs.sqlteam.com/peterl/archive/2009/06/17/How-to-get-the-Nth-weekday-of-a-month.aspx I have fiddled around with it and have now extended the function to find the Nth weekday not only for a month, but also for a quarter or a year. Read more →

I am proud and humble

A few months back, Adam Machanic launched a competition about "Grouped string concatenenation" here http://sqlblog.com/blogs/adam_machanic/archive/2009/02/27/t-sql-challenge-grouped-string-concatenation.aspx Now Adam has publish his results here http://sqlblog.com/blogs/adam_machanic/archive/2009/05/31/grouped-string-concatenation-the-winner-is.aspx and luckily my fourth suggestion was considered the overall winner! Read more →