What will be output of below query?

Select GetDate();
Select DateAdd(DD,15,GetDate());

Answer:

Below will be the output:-

2013-12-04 16:40:50.683
2013-12-19 16:40:50.683

As we can see in the output,Time is Same but Date is Different as 04 December and 19 December.

So, DateAdd as the name implies,adds date to the supplied date.
DateAdd is an in-built Sql-Server function.

Here,DD means day which is a datepart.