[lmikle]

Ну, наверное, можно попробовать так:

Код:

type
  TTimeStamp = packed record
    Time Integer;
    Date Integer;
  end;

function DateTimeToInt64(Value : TDateTime) : Cardinal; // 64-bit unsigned int
var
  ts : TTimeStamp;
begin
  ts.Date := DaysBetween(EncodeDate(1,1,1),DateOf(Value))+1;
  ts.Tme := MilliSecondOf(TimeOf(Value));
  Result := Cardinal(ts);
end;