当前时间减一小时,如何做

Question

当前时间减一小时,如何做,请高手指教

Answer 1

ShowMessage(DateTimeToStr(IncHour(now,-1)) );

Answer 2

//自己写函数
function IncHour(const AValue: TDateTime;
  const ANumberOfHours: Int64): TDateTime;
begin
  Result := ((AValue * 24) + ANumberOfHours) / 24;
end;
ShowMessage(DateTimeToStr(IncHour(now,-1)) );

Answer 3

function IncHour(const AValue: TDateTime;
  const ANumberOfHours: Int64): TDateTime;
begin
  Result := ((AValue * HoursPerDay) + ANumberOfHours) / HoursPerDay;
end;procedure TForm1.Button1Click(Sender: TObject);begin
   showmessage( FormatDateTime('hh:mm:ss', IncHour(Now,-1)))
end;