First, make sure you do not use datatypes as columnnames. Date is a type and using it as a column name is an invitation to trouble.
Try the examples from here
The purpose of this paper is to provide you background on SQL Server. It’s your self-study guide for learning fundamentals. It includes both the history of SQL and its technical basics. Concepts and definitions will form the solid foundation of your future DBA expertise.
Calculating holidays and working days is a function that is often needed yet it is not one found within the Framework. This article presents one approach to building a working-day calculator for use in .NET.
Using examples as well as descriptions, and references to Books Online, show the different Recovery Models available in SQL Server and explain, as well as show how full, differential and transaction log backups are performed
Using examples as well as descriptions, and references to Books Online, show the documentation available for datatypes, explain the available data types and show how data can be passed into and out of variables.