See DATEDIFF() function and use self-join.

>I have a table like this.

>FY     PD        PD_END_DT           DAYS IN PD
>------ ------ ---------------------------
>2002   1      Jan 31 2002 12:00AM         ?
>2002   2      Feb 28 2002 12:00AM
>2002   3      Mar 31 2002 12:00AM
>2002   4      Apr 30 2002 12:00AM
>2002   5      May 31 2002 12:00AM
>2002   6      Jun 30 2002 12:00AM
>2002   7      Jul 31 2002 12:00AM
>2002   8      Aug 31 2002 12:00AM
>2002   9      Sep 30 2002 12:00AM
>2002   10     Oct 31 2002 12:00AM
>2002   11     Nov 30 2002 12:00AM
>2002   12     Dec 31 2002 12:00AM
>2003   1      Jan 31 2003 12:00AM
>2003   2      Feb 28 2003 12:00AM
>2003   3      Mar 31 2003 12:00AM

>I want to find how many days in each period. How can I use SQL to do this?
>
>
>Thanks
>
>
>Jim