How to count last 30 days?

1

select TO_CHAR (TO_DATE(DATE,'YYYYMMDD'), 'DD-MON-YY'),user_id,

CASE
WHEN (flag_1=1 or flag_2=1)

           and   TO_CHAR (TO_DATE(date,'YYYYMMDD'), 'YYYYMMDD') >= TO_CHAR (TO_DATE(date,'YYYYMMDD')-30, 'YYYYMMDD')
                
      THEN 1 else 0 end last_30,

CASE

      WHEN     (flag_1=1 or flag_2=1)                
          
           and    TO_CHAR (TO_DATE(date,'YYYYMMDD'), 'YYYYMMDD') >= TO_CHAR (TO_DATE(date,'YYYYMMDD')-1, 'YYYYMMDD')
                
      THEN 1 else 0 end last_day
    
      from table1
2

duplicates of How to count last 30 days?