How to provide the year based on month

[Sharath_naik]

Hi Team,

Please help me to get year based on month ...... 

In Below example ...... How to get Excepting output Column

Group Month Expecting output
Abc     11            2021
Abc     12            2021
Abc       1            2022
Abc       2            2022
Abc       3            2022
Abc       4            2022
Abc       5           2022
Abc       6           2022
Abc       7           2022
Abc       8           2022
Abc       9           2022
Abc     10           2022
Abc     11           2022
Abc     12          2022
Abc     1            2023
Abc     2            2023
BVC   12          2021
BVC    1           2022
BVC    2           2022
BVC    3           2022
BVC    4          2022
BVC    5         2022
BVC    6          2022
BVC    7          2022
BVC    8          2022
BVC    9          2022
BVC   10         2022
BVC    11        2022
BVC    12        2022
BVC     1        2023
BVC     2        2023

[PaigeMiller]

You can't derive a year from a month without strict rules about how to do this, which you don't explain. Rather than me guess and potentially get it wrong, please explain the logic that creates the expected column.

[andreas_lds]

Using first/last, lag-function and assuming that the data is sorted by "Group":

data want;
   set have;
   by Group;
   
   retain Year;
   
   LastMonth = lag(Month);
   
   if first.Group then do;
      Year = 2021;
      LastMonth = Month - 1;
   end;
   
   if Month ^= LastMonth + 1 then do;
      Year = Year + 1;
   end;
   
   drop LastMonth;
run;

[Kurt_Bremser]

From your data, this should do it:

data want;
set have;
by group;
if first.group then year = 2021;
if month = 1 then year + 1;
run;