FUNCTION def_time_origin, timeave, date1

;
; compute date format : 0010-JAN-01 00:00:00
; date1 code [yy..yyy][mm][dd]-[sssss] if <n>s
;            [yy..yyy][mm][dd] if <n>d
;            [yy..yyy][mm]     if <n>m
;            [yy..yyy]         if <n>y

   len1 = strlen(date1)

   mean_type = strmid(timeave, strlen(timeave)-1,1)
   CASE mean_type OF
      'y':BEGIN                 ; year case
         year1 = long(date1)
         time_origin = string(FORMAT = '(I4)', year1)+'-JAN-01 00:00:00'
      END 
      'm': BEGIN                ; month case
         CASE strmid(timeave, strlen(timeave)-2,1) OF
            'm': BEGIN          ; mean month      
               month1 = long(strmid(date1, 0, 2))
               time_origin = '0000-JAN-01 00:00:00'
            END 
            ELSE: BEGIN         ; month / year     
               month1 = long(strmid(date1, len1-2, 2))
               year1  = long(strmid(date1, 0, len1-2))
               time_origin = string(FORMAT = '(I4.4)', year1)+'-'+trans_month(month1)+'-01 00:00:00'
            END 
         ENDCASE 
      END 
      'd': BEGIN                ; day case
         day1   = strmid(date1, len1-2, 2)
         month1 = long(strmid(date1, len1-4, 2))
         year1  = long(strmid(date1, 0, len1-4))
         time_origin = string(FORMAT = '(I4)', year1)+'-'+trans_month(month1)+'-'+day1+' 00:00:00'
      END 
      's': BEGIN                ; seconds case
         sec1   = long(strmid(date1, len1-5, 5))
         day1   = long(strmid(date1, len1-8, 2))
         month1 = long(strmid(date1, len1-10, 2))
         year1  = long(strmid(date1, 0, len1-10))
         print, '   **** def_time_origin not ready for timeave = ', timeave
      END 
      ELSE: BEGIN
         print, '   **** def_time_origin not ready for timeave = ', timeave
         count = -1
         time = 0
      END 
   ENDCASE 

   return, time_origin

END