오라클 함수, SQL Functions(10g) - Datetime Functions

http://docs.oracle.com/cd/B19306_01/server.102/b14200/functions001.htm#sthref912

1. ADD_MONTHS
2. CURRENT_DATE
3. CURRENT_TIMESTAMP
4. DBTIMEZONE
5. EXTRACT (datetime)
6. FROM_TZ
7. LAST_DAY
8. LOCALTIMESTAMP
9. MONTHS_BETWEEN
10. NEW_TIME
11. NEXT_DAY
12. ROUND (date)
13. SESSIONTIMEZONE
14. SYSDATE
15. SYSTIMESTAMP
16. TO_CHAR (date)
17. TO_TIMESTAMP
18. TRUNC (date)
19. TZ_OFFSET