MonthOfTheYear、WeekOfTheYear、WeekOfTheMonth、DayOfTheYear ... 相对时间

SysUtils.DayOfWeek();

DateUtils.MonthOfTheYear();
DateUtils.WeekOfTheYear();
DateUtils.WeekOfTheMonth();
DateUtils.NthDayOfWeek();
DateUtils.DayOfTheYear();
DateUtils.DayOfTheMonth();
DateUtils.DayOfTheWeek();
DateUtils.SysUtils.DayOfWeek();

DateUtils.HourOfTheYear();
DateUtils.HourOfTheMonth();
DateUtils.HourOfTheWeek();
DateUtils.HourOfTheDay();

DateUtils.MinuteOfTheYear();
DateUtils.MinuteOfTheMonth();
DateUtils.MinuteOfTheWeek();
DateUtils.MinuteOfTheDay();
DateUtils.MinuteOfTheHour();

DateUtils.SecondOfTheYear();
DateUtils.SecondOfTheMonth();
DateUtils.SecondOfTheWeek();
DateUtils.SecondOfTheDay();
DateUtils.SecondOfTheHour();
DateUtils.SecondOfTheMinute();

DateUtils.MilliSecondOfTheYear();
DateUtils.MilliSecondOfTheMonth();
DateUtils.MilliSecondOfTheWeek();
DateUtils.MilliSecondOfTheDay();
DateUtils.MilliSecondOfTheHour();
DateUtils.MilliSecondOfTheMinute();
DateUtils.MilliSecondOfTheSecond();

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses DateUtils;

procedure TForm1.FormCreate(Sender: TObject);
var
  t: TDateTime;
  w: Word;
  c: Cardinal;
  i: Int64;
begin
  t := StrToDateTime('2009-5-20 11:22:33');

  {指定时间是年度第几月份}
  w := MonthOfTheYear(t);  //5

  {指定时间分别是年、月的第几周}
  w := WeekOfTheYear(t);  //21
  w := WeekOfTheMonth(t); //3
  w := NthDayOfWeek(t);   //3

  {指定时间分别是年、月、周的第几天}
  w := DayOfTheYear(t);   //140
  w := DayOfTheMonth(t);  //20
  w := DayOfTheWeek(t);   //3
  w := SysUtils.DayOfWeek(t); //4; DayOfWeek 和 DayOfTheWeek 类似, 但算法不同

  {指定时间分别是年、月、周、日的第几小时}
  w := HourOfTheYear(t);  //3347
  w := HourOfTheMonth(t); //467
  w := HourOfTheWeek(t);  //59
  w := HourOfTheDay(t);   //11

  {指定时间分别是年、月、周、日、时的第几分钟}
  c := MinuteOfTheYear(t);  //200842
  w := MinuteOfTheMonth(t); //28042
  w := MinuteOfTheWeek(t);  //3562
  w := MinuteOfTheDay(t);   //682
  w := MinuteOfTheHour(t);  //22

  {指定时间分别是年、月、周、日、时、分的第几秒}
  c := SecondOfTheYear(t);   //12050553
  c := SecondOfTheMonth(t);  //1682553
  c := SecondOfTheWeek(t);   //213753
  c := SecondOfTheDay(t);    //40953
  w := SecondOfTheHour(t);   //1353
  w := SecondOfTheMinute(t); //33

  {指定时间分别是年、月、周、日、时、分、秒的第几毫秒}
  i := MilliSecondOfTheYear(t);   //12050553000
  c := MilliSecondOfTheMonth(t);  //1682553000
  c := MilliSecondOfTheWeek(t);   //213753000
  c := MilliSecondOfTheDay(t);    //40953000
  c := MilliSecondOfTheHour(t);   //1353000
  c := MilliSecondOfTheMinute(t); //33000
  w := MilliSecondOfTheSecond(t); //0
end;

end.

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DateUtils-Function

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