Date:         Thu, 4 Dec 2008 12:20:17 -0800
Reply-To:     Akshaya <akshaya.nathilvar@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Akshaya <akshaya.nathilvar@GMAIL.COM>
Organization: http://groups.google.com
Subject:      Re: manipulating data
Comments: To: sas-l@uga.edu
Content-Type: text/plain; charset=ISO-8859-1

If the data is nicely sorted as in your example, then

Data have;
    input date mmddyy10.;
    month=month(date);
    format date mmddyy10.;
cards;
01/15/2008
01/17/2008
01/26/2008
02/01/2008
02/05/2008
02/25/2008
;

Data want;
    set have;
    by month;
    if last.month;
Run;

Thanks!
Akshaya