USAGE
   signed int sccdsvalid(
           signed char *string,
           signed int format );
PROTOTYPE IN
   sc_clock.h

DESCRIPTION
   sccdsvalid tests the date ASCIIZ string passed for validity:
   string properly formatted (format), valid day of month, and valid month
   of year.

   Date string styles:
   SC_GREGOR     mm/dd/yy
   SC_GREGORL    mm/dd/yyyy
   SC_JULIAN     yyyy/ddd
   SC_YMD        yyyymmdd
   SC_DMY        ddmmyy

EXAMPLE
   #include <stdio.h>
   #include <softc.h>
   #include <sc_clock.h>

   void main()
   {
     if (sccdsvalid("19890213" SC_YMD) == SC_SUCCESS)
       puts("Good Date.");
     else
       puts("Bad Date.");
   }