SQL Server Arithmetic Operators (+)

(+) addition arithmetic operator is used to add two numbers, also adds a number either in days or in a date.

DECLARE @someNumber int; SET @someNumber = 191;
SELECT '200' + @someNumber;

Result = 391 

DECLARE @initialdate datetime, @someNumber int;
SET @initialdate = ''June 26, 1982 07:33 AM';
SET @someNumber = 3;
SELECT @initialdate + @someNumber AS 'Final Date';
Result = 1982-06-29 07:33:00.000