SQL Left Join Within Timeframe Window

Question

I have two datasets:

dataset_a
time_stamp                   user    group    value
2021-06-20 12:48:24.521         A    video        1
2021-06-15 12:50:24.521         A    video        1
2021-06-10 12:48:24.521         A    video        1    

dataset_b
time_stamp                   user    group    label
2021-06-20 09:40:24.521         A    video       BA
2021-06-19 13:30:24.521         A    video       BB  
2021-06-13 12:48:24.521         A    video       BC  
2021-06-09 12:55:24.521         A    video       BD   

I want to create a dataset where if dataset b is within 1 day of timestamp of dataset a by timestamp, user, and group then it is a match. Has anyone done something like this before where it is something like left join on dataset_b.timestamp between dataset_a.timestamp and date_add(dataset_a.timestamp,-1). I'd like to have the flexibility where in the future I can test out -7 days as well so it is easily modifiable.

Expected output below:

 dataset_a
time_stamp                   user    group    value    timestamp_b               label
2021-06-20 12:48:24.521         A    video      0.5    2021-06-20 09:40:24.521      BA
2021-06-20 12:48:24.521         A    video      0.5    2021-06-19 13:30:24.521      BB
2021-06-15 12:50:24.521         A    video        1    NULL                       NULL   
2021-06-10 12:48:24.521         A    video        1    2021-06-09 12:55:24.521      BD    

Answer 1

The JOIN condition does not have to be only equality operator so:

SELECT *
FROM dataset_a
LEFT JOIN dataset_b
  ON dataset_b.user = dataset_a.user
 AND dataset_b.group = dataset_a.group
 AND dataset_b.time_stamp BETWEEN dataset_a.time_stamp - INTERVAL '1 day'
                              AND dataset_a.time_stamp ;

is a valid join.

db<>fiddle demo