How far we can flashback - oracle database script

How far we can flashback - Oracle Database Script.

--How Far Back Can We Flashback To (Time)  select to_char(oldest_flashback_time,’dd-mon-yyyy hh24:mi:ss’) “Oldest Flashback Time” from v$flashback_database_log;  --How Far Back Can We Flashback To (SCN)  col oldest_flashback_scn format 99999999999999999999999999 select oldest_flashback_scn from v$flashback_database_log;