INT 21 - DOS 1+ - SET SYSTEM TIME
AH = 2Dh
CH = hour
CL = minute
DH = second
DL = 1/100 seconds
Return: AL = result
00h successful
FFh invalid time, system time unchanged
Note:   DOS 3.3+ also sets CMOS clock
SeeAlso: AH=2Ch,INT 1A/AH=01h,INT 1A/AH=03h,INT 1A/AH=FFh"AT&T"

See also: 212B

212D - DOS 1+ - SET SYSTEM TIME