How to find difference between datetime in a single column

[Siva_Harish]

Hi ,

How to get same id presented same topic_id within  within (less than) 45 days.

Can anyone help me on this?

ID	EVENT_START_DATE	TOPIC_ID
4	18Sep2019 14:30:00	427EP1905697-01
4	18Dec2019 15:15:00	427EP1905697-01
4	21Feb2020 18:30:00	427EP1905697-01
4	18Sep2019 14:30:00	427ES18PR07337-01
4	18Dec2019 15:15:00	427ES18PR07337-01
4	21Feb2020 18:30:00	427ES18PR07337-01
4	18Sep2019 14:30:00	IMSES18PR03522-01
4	18Dec2019 15:15:00	IMSES18PR03522-01
4	21Feb2020 18:30:00	IMSES18PR03522-01
6	12Sep2019 17:30:00	427EP1905697-01
6	18Sep2019 14:30:00	427EP1905697-01
6	18Dec2019 15:15:00	427EP1905697-01
6	12Sep2019 17:30:00	427ES18PR07337-01
6	18Sep2019 14:30:00	427ES18PR07337-01
6	18Dec2019 15:15:00	427ES18PR07337-01
6	12Sep2019 17:30:00	IMSES18PR03522-01
6	18Sep2019 14:30:00	IMSES18PR03522-01
6	18Dec2019 15:15:00	IMSES18PR03522-01

[Kurt_Bremser]

Apply the same basic technique I showed you here.

[PaigeMiller · Accepted solution]

Assuming your EVENT_START_DATE is truly numeric date/time values in SAS, and assuming your data is properly sorted by ID and TOPIC_ID, you can use the DIF Function.

data want;
    set have;
    by id topic_id;
    delta=dif(event_start_date);
    if not first.topic_id and delta<45*86400 then flag='Less than 45 days';
    drop delta;
run;
    

[Reeza]

Self join - you can join a table with itself.