Subtracting dates by row and id

[mmaleta851]

Hi there. I am trying to subtract dates by row as shown here:

PlayerID	Date
1001	12JUN2020
1001	11JUN2020
1002	24AUG2020
1002	13JUL2020
1003	17MAY2021

What I want is this:

PlayerID	Date	DateDiff
1001	12JUN2020	.
1001	11JUN2020	1
1002	24AUG2020	.
1002	13JUL2020	42

However, when I run this code

data table;
input PlayerID$ Date:date9.;

format Date date9.;
datalines;
1001 12JUN2021
1001 11JUN2021
1002 24AUG2020
1002 13JUL2020
;
pro sort data = table;

by PlayerID Date DESC;

run;

data datediff;
set table;
by PlayerID;
daydiff=abs(dif(Date));
if not first.PlayerID then output;
run;

It substracts the previous date regardless like this:

PlayerID	Date	DateDiff
1001	12JUN2020
1001	11JUN2020	1
1002	24AUG2020	223
1002	13JUL2020	42

Any ideas on how to resolve this?

[PaigeMiller · Accepted solution]

daydiff=abs(dif(Date));
if first.PlayerID then daydiff=.;