Function            time_convert - convert time formats

  Syntax              boolean time_convert(void *source, void *dest,
                                           int stype, int dtype);

  Prototype in        timehk.h

  Remarks             time_convert will convert a time from virtually any
                      time format to any other. The parameters *source
                      and *dest must be pointers pointing to a piece of
                      memory allocated as the proper data type. stype and
                      dtype determine the format of source and dest.

                      Due to the great number of formats supported, a
                      chart of valid time formats is provided in Appendix
                      C.

                      Limited error checking is done on passed data. If
                      an invalid time format is passed, unpredictable
                      results will occur.

  Return value        returns TRUE is the conversion was successful and
                      FALSE if the time could not be converted.

  Note                This function does NO function calls. I've tried to
                      optimize this function as much as possible for
                      speed, not size. If you only need to convert
                      between a couple of specific formats, you may be
                      better off doing a pair of sprintfs.

  See also            Appendix C
                      strtotime(), timetostr()

  Example             see demotime.c