Special oracle to_date formatting

Special formatting of oracle to_date SQL code select to_date ('mon Jan 28 11:25:58 CST 2013 ', 'dy Mon DD HH24: MI: SS "CST" YYYY') from dual if an error is prompted, if the encoding is incorrect, run the SQL code alter session set nls_date_language = 'American '; -- Obtain the select to_char (next_day (sysdate, 1) for the week where the specified date is located) -6, 'yyyy/mm/dd') aa, to_char (next_day (sysdate, 1)-6 + 6, 'yyyy/mm/dd ') bb from dual -- Obtain the Monday of the specified date. Sunday belongs to the previous week. The start day of the week is calculated as Monday. select next_day (sysdate, 'monday')-7 from dual