insert date to database

how to write a gava code that insert a system date into oracle daatbase
this is my database table:
CREATE DIMENSION times_dim
   LEVEL day         IS TIMES.TIME_ID
   LEVEL month       IS TIMES.CALENDAR_MONTH_DESC
   LEVEL quarter     IS TIMES.CALENDAR_QUARTER_DESC
   LEVEL year        IS TIMES.CALENDAR_YEAR
   LEVEL fis_week    IS TIMES.WEEK_ENDING_DAY
   LEVEL fis_month   IS TIMES.FISCAL_MONTH_DESC
   LEVEL fis_quarter IS TIMES.FISCAL_QUARTER_DESC
   LEVEL fis_year    IS TIMES.FISCAL_YEAR
   HIERARCHY cal_rollup    (
             day     CHILD OF
             month   CHILD OF
             quarter CHILD OF
             year
   )
   HIERARCHY fis_rollup    (
             day         CHILD OF
             fis_week    CHILD OF
             fis_month   CHILD OF
             fis_quarter CHILD OF
             fis_year
   );