SQL Server: First Day of Previous Month

A user asked me how to find the first day of the previous and next month in SQL Server. It’s quite simple as explained in Itzik’s excellent book Inside Microsoft SQL Server 2008: T-SQL Programming (Pro-Developer).

Here’s the query

Here’s the same query to try out:

-- To Get First Day of Previous Month
SELECT DATEADD(MONTH, DATEDIFF(MONTH, '19000101', GETDATE()) - 1, '19000101')
as [First Day Previous Month];
GO

-- To Get First Day of Next Month
SELECT DATEADD(MONTH, DATEDIFF(MONTH, '19000101', GETDATE()) + 1, '19000101')
as [First Day Next Month];
GO

To understand what we just did, first execute the following query:

SELECT DATEDIFF(MONTH, '19000101', GETDATE())

This query returns 1333 (as of this writing) which is the number of months since 1/1/1900. Since we want to calculate a day of the previous month, subtract 1. To calculate a day of the next month, add 1. That’s it, now use the DATEADD function to return a specified date with the number interval (1333) subtracted or added to the datepart (month) of 1/1/1900.

OUTPUT

You may also want to check

SQL Server: First and Last Sunday of Each Month

Find First and Last Day of the Current Quarter in SQL Server

About The Author

Suprotim Agarwal, MCSD, MCAD, MCDBA, MCSE, is the founder of DotNetCurry, DNC Magazine for Developers, SQLServerCurry and DevCurry. He has also authored a couple of books 51 Recipes using jQuery with ASP.NET Controls and a new one recently at The Absolutely Awesome jQuery CookBook.

Suprotim has received the prestigous Microsoft MVP award for nine times in a row now. In a professional capacity, he is the CEO of A2Z Knowledge Visuals Pvt Ltd, a digital group that represents premium web sites and digital publications comprising of Professional web, windows, mobile and cloud developers, technical managers, and architects.

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