NAME
	CheckDate -- checks a ClockData structure for legal date. (V36)

   SYNOPSIS
	seconds = CheckDate(date);
	D0                  A0

	ULONG CheckDate(struct ClockData *);

   FUNCTION
	Determines if the ClockData structure contains legal date information
	and returns the number of seconds from 01-Jan-1978 to that date, or 0
	if the ClockData structure contains illegal data.

   INPUTS
	date - a filled-in ClockData structure

   RESULTS
	seconds	- 0 if date is invalid, otherwise the number of seconds from
		  01-Jan-1978 to the date

   BUGS
	The wday field of the ClockData structure is not checked.

   SEE ALSO
	Amiga2Date(), Date2Amiga()