Creating time var

[deleted_user]

I have a data set that is in the long format

ID Date
001 10/01/2007
001 01/02/2008
002 01/15/2008
002 02/20/2008
002 08/09/2008

I need to create a new variable called time that identifies for each subject whether their clinic visit (Date variable) represents their first visit, second visit etc

ID Date Time
001 10/01/2007 1
001 01/02/2008 2
002 01/15/2008 1
002 02/20/2008 2
002 08/09/2008 3

Can anyone kindly help me with this

[LinusH]

Try this:

data visits;
input id date;
informat date mmddyy10.;
format date mmddyy10.;
datalines;
001 10/01/2007
001 01/02/2008
002 01/15/2008
002 02/20/2008
002 08/09/2008
;
run;

data vistsno;
set visits;
by id;
if first.id then noVisit = 0;
noVisit + 1;
run;

/Linus

[deleted_user]

Linus, you're a genius!!!! Works like a charm! I have been slaving over this for days. Thank you!