Function            Greg... - family of Gregorian date conversion
                                  functions

  Syntax              double GregtoCal(char *greg);
                      double GregtoCalCent(char *greg);

                      double GregEurotoCal(char *greg);
                      double GregEurotoCalCent(char *greg);

                      double GregJaptoCal(char *greg);
                      double GregJaptoCalCent(char *greg);

  Prototype in        datehk.h

  Remarks             GregtoCal      converts Gregorian (US) dates to
                                     Calendar dates
                      GregtoCalCent       converts Gregorian (US) dates
                                          to Calendar dates (w/century)

                      GregEurotoCal       converts Gregorian (European)
                                          dates to Calendar dates
                      GregEurotoCalCent   converts Gregorian (European)
                                          dates to Calendar dates
                                          (w/century)

                      GregJaptoCal        converts Gregorian (Japan)
                                          dates to Calendar dates
                      GregJaptoCalCent    converts Gregorian (Japan)
                                          dates to Calendar dates
                                          (w/century)

  Return value        GregtoCal, GregEurotoCal, GregJaptoCal return a
                           Calendar date
                      GregtoCalCent, GregEurotoCalCent, GregJaptoCalCent
                           return a Calendar date (w/century)

  See also            Appendix A
                      Cal...(), date_convert(), ddatetofull(),
                      ddatetoshort(), ddatetostr(), fulltoddate(),
                      Jul...(), monthexpand(), shorttoddate(),
                      strtoddate()

  Example             see demodate.c