Use the below query to determine when a particular table was created in Redshift database. Replace <your schema name> with the name of your schema and <your table name> with the name of the table that you would like to determine the creation time for.
SELECT nspname AS schema_name, relname AS table_name, relcreationtime AS creation_time FROM pg_class_info c, pg_namespace n WHERE c.relnamespace=n.oid AND reltype != 0 AND nspname='<your schema name>' AND relname=<your table name>';