INT 21 - DOS 1+ - SET SYSTEM DATE AH = 2Bh CX = year (1980-2099) DH = month (1-12) DL = day (1-31) Return: AL = status 00h successful FFh invalid date, system date unchanged Note: DOS 3.3+ also sets CMOS clock; due to the limitations of the CLOCK$ driver interface, the CMOS time is also updated to the current DOS time (which is the BIOS time-of-day clock with the default CLOCK$ driver) SeeAlso: AH=2Ah,AH=2Dh,INT 1A/AH=05h