"Days" are the days between each date of sale and the previous one. I need to understand the average number of days that pass between one sale and another for the PV, still considering the last six months for each date of sale. Here what I expect to have: pv date date - 180 days days mean_days WRONG mean days CORRECT 2011164 02-mar-23 03-set-22 0 . 0 2011164 22-mar-23 23-set-22 20 10 0 2011164 06-apr-23 08-ott-22 15 7.5 10 2011164 21-apr-23 23-ott-22 15 7.5 11,66666667 2011164 05-mag-23 06-nov-22 14 7 12,5 2011164 18-mag-23 19-nov-22 13 6.5 12,8 2011164 01-giu-23 03-dic-22 14 7 12,83333333 2011164 15-giu-23 17-dic-22 14 7 13 2011164 30-giu-23 01-gen-23 15 7.5 13,125 2011164 14-lug-23 15-gen-23 14 7 13,33333333 2011164 28-lug-23 29-gen-23 14 7 13,4 2011164 18-ago-23 19-feb-23 21 10.5 13,45454545 2011164 04-set-23 08-mar-23 17 8.5 15,36363636 2011164 20-set-23 24-mar-23 16 8 15,09090909   ... View more

Great! Just one last question. What type of change I need in the code below if I want to calculate for each pv and for each date the mean of the days? It seems to work but the results are wrong.   data freq; set dataset; by pv; array s {&start.:&end.} _temporary_; if first.pv then do i = &start. to &end.; s{i} = .; end; s{data} = mean(s{data},days); do i = intnx("day",data,-180,"s") to data - 1; freq = mean(days,s{i}); end; format i date9.; *drop i; run;   Here the sample of data (here mean_days is not correct): pv date   days mean_days 2011164 02-mar-23 03SEP2022 . . 2011164 22-mar-23 23SEP2022 20 10 2011164 06-apr-23 08OCT2022 15 7.5 2011164 21-apr-23 23OCT2022 15 7.5 2011164 05MAY2023 06-nov-22 14 7 2011164 18MAY2023 19-nov-22 13 6.5 2011164 01JUN2023 03DEC2022 14 7 2011164 15JUN2023 17DEC2022 14 7 2011164 30JUN2023 01JAN2023 15 7.5 2011164 14JUL2023 15JAN2023 14 7 2011164 28JUL2023 29JAN2023 14 7 2011164 18AUG2023 19-feb-23 21 10.5 2011164 04SEP2023 08-mar-23 17 8.5   Thanks in advance. ... View more

WOW, it works. I need two adjustments: the first one is that the sellin doesn't have to consider the sales of the day (so for example, for today it has to consider the sales from yesterday up to 6 months ago) - see the SALES_SUM6 of the last 3 rows of the table; the other adjustment is that the variable SALES_SUM6 needS to be null if for a given date there isn't a history of at least 6 months (in our case all the dates up to 18AUG2023 need to have SALES_SUM6 null because 18AUG2023 - 180 days is 19FEB2024 and our data starts from 02MAR2023 and it is ok ) - see the first rows of the table. See the table to understand the 2 adjustments: PV DATE SELLIN 6MONTHSAGO SALES_SUM6 2011164 02-mar-23 2250 03SEP2022 0 2011164 22-mar-23 2325 23SEP2022 0 2011164 06-apr-23 2475 08OCT2022 0 2011164 21-apr-23 2850 23OCT2022 0 2011164 05MAY2023 2475 06-nov-22 0 2011164 18MAY2023 2400 19-nov-22 0 2011164 01JUN2023 2475 03DEC2022 0 2011164 15JUN2023 2175 17DEC2022 0 2011164 30JUN2023 2250 01JAN2023 0 2011164 14JUL2023 2475 15JAN2023 0 2011164 28JUL2023 2100 29JAN2023 0 2011164 18AUG2023 1125 19-feb-23 26250 2011164 04SEP2023 2025 08-mar-23 25125 2011164 20SEP2023 2550 24-mar-23 24825   I hope my explanation is clear and there is a solution ofr my requests. Thank you so much! I'm very grateful ... View more