qa.hlp (Table of Contents; Topic list)
Int 21H Function 57H
   Summary  Notes  Example  Back
──────────────────────────────────────────────────────────────────────────────
 
▀ The file must have been previously opened or created via a successful
  call to Int 21H Function 3CH, 3DH, 5AH, 5BH, or 6CH.
 
▀ If the 16-bit date for a file is set to zero, that file's date and time
  are not displayed on directory listings.
 
▀ A date and time set with this function will prevail, even if the file is
  modified afterwards before the handle is closed.
                                    -♦-