unit1.pas

判断一个月的月底和每天的0点

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls, StdCtrls;

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Button1: TButton;
    Label1: TLabel;
    Timer1: TTimer;
    Edit2: TEdit;
    procedure Timer1Timer(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

function   firstdayofmonth(dat:   tdate):   tdate;
var
  d,m,y:word;
begin
  decodedate(incmonth(dat,1),y,m,d);
  result:=encodedate(y,m,1);
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
  Label1.Caption:=DatetimeToStr(now);
  if DateTimeToStr(now - date) = '1899-12-30' then
    Edit1.Text := '0点到啦～～～'+DateTimeToStr(now);
  //月末最后一天的日期
//  edit1.text :=DateToStr(lastdayofmonth(date));
  if DatetimeToStr(now-firstdayofmonth(date))='1899-12-30' then
    Edit2.Text := '月底到啦～～～'+DateTimeToStr(now);
end;

end.