My sample to "COUNTDOWN" between 2 TDateTime values

[Guest]

My sample to "COUNTDOWN" between 2 TDateTime values:

• the "countdown" to hh:mm:ss it's ok!
• I not certain about the values is correct to: years, months and days
  • needs more Math for this...

 

 

source code

implementation

{$R *.dfm}

uses
  System.DateUtils;

var
  lDTFuture: TDateTime;
  lDTnow   : TDateTime;
  //
  lMyFS: TFormatSettings;

procedure TForm2.Button1Click(Sender: TObject);
begin
  lMyFS                := TFormatSettings.Create; // dont needs "Free it"
  lMyFS.LongTimeFormat := 'hh:mm:ss.zzz';         // defining new format for "LongTimeFormat" values when showing it! pass it as "last" param for funtions!
  //
  lDTFuture := StrToDateTimeDef('31/12/2020 00:00:00.000', now, lMyFS); // avoid "AV"
  lDTnow    := StrToDateTimeDef('30/12/2019 23:59:50.000', now, lMyFS); // avoid "AV"
  //
  Timer1.Enabled := true;
end;

procedure TForm2.Timer1Timer(Sender: TObject);
var
  lYears  : word;
  lMonths : word;
  lDays   : word;
  lHours  : word;
  lMinutes: word;
  lSeconds: word;
begin
  if (lDTFuture <= lDTnow) then
  begin
    Timer1.Enabled := false;
    //
    ShowMessage('The time-is-out...');
    //
    exit;
  end;
  //
  Edit2.Text := DateTimeToStr(lDTnow, lMyFS);
  Edit3.Text := DateTimeToStr(lDTFuture, lMyFS);
  //
  // the big problem here with many calculate necessary to verify the values valids: 31days-1 ... = month-1 ... 12month-1 = years-1 etc... verify 28,29,30,31 days 
  // then my minimalisct code was not enought
  lYears   := System.DateUtils.YearsBetween(lDTFuture, lDTnow) mod 1000;
  lMonths  := System.DateUtils.MonthsBetween(lDTFuture, lDTnow) mod 12;
  lDays    := System.DateUtils.DaysBetween(lDTFuture, lDTnow) mod DaysPerYear[System.DateUtils.IsInLeapYear(lDTnow)];
  //
  // here the "countdown" works as expected!
  lHours   := System.DateUtils.HoursBetween(lDTFuture, lDTnow) mod 24;
  lMinutes := System.DateUtils.MinutesBetween(lDTFuture, lDTnow) mod 60;
  lSeconds := System.DateUtils.SecondsBetween(lDTFuture, lDTnow) mod 60;
  //
  Edit1.Text := Format('%d years, %d months, %d days, %d hours, %d minutes, %d seconds', [lYears, lMonths, lDays, lHours, lMinutes, lSeconds]);
  //
  lDTnow := lDTnow + 0.00001; // would be better use "NOW" as current value! // IncSeconds() or MilliSeconds
end;

 

hug

Edited December 13, 2020 by Guest

[FPiette 367]

4 hours ago, emailx45 said:

lHours := System.DateUtils.HoursBetween(lDTFuture, lDTnow) mod 24;

Using mod defeat all the purpose.

Assuming now is sunday 08:07 and future is tuesday 09:20 there are 49 hours (Minutes truncated). Your formula will give 1 hour.

Same for all your calculations.

[Guest]

to Hours, Minutes and Seconds, it's ok! using "mod" operator! the "countdown" works as expected!

Just Years, Months and Days NOT because the many possibilities in this calculate!

 

   

Edited December 13, 2020 by Guest