Earlier I wrote a blog post about SQL SERVER – Query to Find First and Last Day of Current Month and it is a very popular post. In this post, I convert the datetime to Varchar and later on use it. However, SQL Expert Michael Usov has made a good point suggesting that it is not always a good idea to convert datetime to any other date format as it is quite possible that we may need it the value in the datetime format for other operation. He has suggested a very quick solution where we can get the first day of the current month with or without time value and keep them with datatype datetime.
Here is the simple script for the same.
-- first day of month
-- with time zeroed out
SELECT CAST(DATEADD(DAY,-DAY(GETDATE())+1, CAST(GETDATE() AS DATE)) AS DATETIME)
-- with time as it was
SELECT DATEADD(DAY,-DAY(GETDATE())+1, CAST(GETDATE() AS DATETIME))
Here is the resultset:
Reference: Pinal Dave (http://blog.SQLAuthority.com)