Compatibility: 1.0+
Expects: AH    2bH
CX    year (1980 to 2099)
DH    month (1 to 12)
DL    day (1 to 31)
Returns: AL    0    if date was valid
0ffH if date was invalid (30 day values hath September...)
Info: Sets the DOS system date.  The system time is not changed.

Versions:   DOS 3.3+  On AT and PS/2 systems, this also sets the date in
the battery-backed CMOS memory.

See Also: Fn 2cH (set time)
Fn 2aH (set date)
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DOS Fn 2bH: Set DOS Date