@@DATEFIRST in SQL Server will returns the current value, for the session, of SET DATEFIRST.SET DATEFIRST indicates the specified first day of each week.
The U.S. English default is 7, Sunday.
Language settings affect date information. In the following example, the language is first set to italian.
SELECT @@DATEFIRST returns 1.
The language is then set to us_english.
SELECT @@DATEFIRST returns 7.
