Function 57h (87)        Get or Set a File's Date and Time

Gets or sets a file's date and time.

To get a file's date and time:

On entry:      AH         57h
AL         00h
BX         File handle

Returns:       AX         Error code   if CF is set
CX         Time
DX         Date

To set a file's date and time:

On entry:      AH         57h
AL         01h
BX         File handle
CX         Time
DX         Date

Returns:       AX         Error code   if CF is set

Error codes:   1          Invalid function number in AL
6          Invalid handle

                                                                          

Function 57h gets or sets the date and time for a file that has been
opened with a file handle (such as with function 3Dh).

The date and time are defined as follows:

CX = Time = Hour * 2048 + Minute * 32 + Second / 2
DX = Date = (Year - 1980) * 512 + Month * 32 + Day

             CX Bits           Description
11 - 15           Hours (0..23)
5 - 10           Minutes (0..59)
0 - 4            Seconds/2 (0..30)

             DX Bits           Description
9 - 15           Year since 1980 (0..119)
5 - 8            Month (1..12)
0 - 4            Day (1..31)

Notes:         Contrary to what some DOS documentation says, the
date and time are returned in the conventional
format, with the high-order part in CH and DH and
the low-order part in CL and DL.

See also: 3Dh
See also: 59h

57h (87) Get or Set a File's Date and Time