 <p>SQL server specially don't have any function to add and subtract time but if you need you can use </p> <pre><code>DATE_SUB() DATE_ADD() </code></pre> <p>By putting same date in each time <a href="http://www.w3schools.com/sql/func_date_add.asp" rel="nofollow">http://www.w3schools.com/sql/func_date_add.asp</a></p> <p><a href="http://www.w3schools.com/sql/func_date_sub.asp" rel="nofollow">http://www.w3schools.com/sql/func_date_sub.asp</a></p>