(Delphi ActiveX) Compute Difference Between Two DateTime Strings

Demonstrates how to compute the difference between two datetime strings.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
t1: WideString;
t2: WideString;
sb1: TChilkatStringBuilder;
count: Integer;
sb2: TChilkatStringBuilder;
dt1: TCkDateTime;
dt2: TCkDateTime;
diffSeconds: Integer;

begin
// Imagine we have these strings:

t1 := '2022-11-14 15:45:38';
t2 := '2022-11-16 17:23:41';

// How many minutes are between the two?

// First, we'd want load each date/time into a Chilkat CkDateTime object.
// In this case, there are no CkDateTime methods that accept the above format.
// However.. the CkDateTime's SetFromTimestamp will accept a date in the format "YYYY-MM-DDThh:mm:ssZ"

// First modify the above dates to the timestamp format.
sb1 := TChilkatStringBuilder.Create(Self);
sb1.Append(t1);
count := sb1.Replace(' ','T');
sb1.Append('Z');

sb2 := TChilkatStringBuilder.Create(Self);
sb2.Append(t2);
count := sb2.Replace(' ','T');
sb2.Append('Z');

// Load each into a CkDateTime
dt1 := TCkDateTime.Create(Self);
dt1.SetFromTimestamp(sb1.GetAsString());
// verify...
Memo1.Lines.Add(dt1.GetAsTimestamp(0));

dt2 := TCkDateTime.Create(Self);
dt2.SetFromTimestamp(sb2.GetAsString());
// verify...
Memo1.Lines.Add(dt2.GetAsTimestamp(0));

// Get the difference in seconds
diffSeconds := dt2.DiffSeconds(dt1.ControlInterface);
Memo1.Lines.Add('Difference in seconds: ' + IntToStr(diffSeconds));
Memo1.Lines.Add('Difference in minutes: ' + IntToStr(diffSeconds / 60));
end;