INT 21,2D - Set Time

	AH = 2D
	CH = hour (0-23)
	CL = minutes (0-59)
	DH = seconds (0-59)
	DL = hundredths (0-99)


	on return:
	AL = 00 if time change successful
	   = FF if time invalid


	- changes DOS maintained clock
	- DOS version 3.3+ also update CMOS clock where applicable