mov bx, Handle ;handle of file
mov ax, 5700h ;Get Date and Time
int 21h
jc error_handler ;carry set means error
mov FileTime, cx ;time file was last modified
mov FileDate, dx ;date file was last modified
Get File Date and Time (Function 5700h) retrieves the time and date a file was last modified (the last time its directory entry was updated).
Handle
Identifies the file to retrieve the date and time for.
If the function is successful, the carry flag is clear, the CX register contains the time the file was last modified, and the DX register contains the date the file was last modified. Otherwise, the carry flag is set and the AX register contains an error value, which may be 0006h (ERROR_INVALID_HANDLE).
The file time returned in CX is a 16-bit value with the following format:
| Bits | Contents |
| 0–4 | Second divided by 2 |
| 5–10 | Minute (0–59) |
| 11–15 | Hour (0–23 on a 24-hour clock) |
The file date returned in DX is a 16-bit value with the following format:
| Bits | Contents |
| 0–4 | Day of the month (1–31) |
| 5–8 | Month (1 = January, 2 = February, etc.) |
| 9–15 | Year offset from 1980 (add 1980 to get actual year) |
Function 5701h Set File Date and Time