DateTime.DayOfYear プロパティ

定義

このインスタンスで表される年間積算日を取得します。Gets the day of the year represented by this instance.

public:
 property int DayOfYear { int get(); };
public int DayOfYear { get; }
member this.DayOfYear : int
Public ReadOnly Property DayOfYear As Integer

プロパティ値

1 から 366 までの間の積算日。The day of the year, expressed as a value between 1 and 366.

次の例では、グレゴリオ暦の2010-2020 年の年12月31日を表示します。The following example displays the day of the year of December 31 for the years 2010-2020 in the Gregorian calendar. この例では、12月31日がうるう年の年の36番目の日であることが示されています。Note that the example shows that December 31 is the 366th day of the year in leap years.

using System;

public class Example
{
   public static void Main()
   {
      DateTime dec31 = new DateTime(2010, 12, 31);
      for (int ctr = 0; ctr <= 10; ctr++) {
         DateTime dateToDisplay = dec31.AddYears(ctr);
         Console.WriteLine("{0:d}: day {1} of {2} {3}", dateToDisplay, 
                           dateToDisplay.DayOfYear,
                           dateToDisplay.Year,   
                           DateTime.IsLeapYear(dateToDisplay.Year) ? 
                                               "(Leap Year)" : ""); 
      }  

   }
}
// The example displays the following output:
//       12/31/2010: day 365 of 2010
//       12/31/2011: day 365 of 2011
//       12/31/2012: day 366 of 2012 (Leap Year)
//       12/31/2013: day 365 of 2013
//       12/31/2014: day 365 of 2014
//       12/31/2015: day 365 of 2015
//       12/31/2016: day 366 of 2016 (Leap Year)
//       12/31/2017: day 365 of 2017
//       12/31/2018: day 365 of 2018
//       12/31/2019: day 365 of 2019
//       12/31/2020: day 366 of 2020 (Leap Year)
Option Strict On

Module Example
   Public Sub Main()
      Dim dec31 As Date = #12/31/2010#
      For ctr As Integer = 0 To 10
         Dim dateToDisplay As Date = dec31.AddYears(ctr)
         Console.WriteLine("{0:d}: day {1} of {2} {3}", dateToDisplay, 
                           dateToDisplay.DayOfYear,
                           dateToDisplay.Year,   
                           If(DateTime.IsLeapYear(dateToDisplay.Year), 
                                                  "(Leap Year)", "")) 
                           
      Next
   End Sub
End Module
' The example displays the following output:
'       12/31/2010: day 365 of 2010
'       12/31/2011: day 365 of 2011
'       12/31/2012: day 366 of 2012 (Leap Year)
'       12/31/2013: day 365 of 2013
'       12/31/2014: day 365 of 2014
'       12/31/2015: day 365 of 2015
'       12/31/2016: day 366 of 2016 (Leap Year)
'       12/31/2017: day 365 of 2017
'       12/31/2018: day 365 of 2018
'       12/31/2019: day 365 of 2019
'       12/31/2020: day 366 of 2020 (Leap Year)

注釈

@No__t-0 プロパティは、年の日付を計算するときに、うるう年を考慮します。The DayOfYear property takes leap years into account when it calculates the day of the year. プロパティ値は、現在のスレッドカルチャの現在の暦に関係なく、グレゴリオ暦の年の日付を常に反映します。The property value always reflects the day of the year in the Gregorian calendar, regardless of the current thread culture's current calendar. 別の暦で年の日付を取得するには、その暦の Calendar.GetDayOfYear メソッドを呼び出します。To retrieve the day of the year in a different calendar, call the Calendar.GetDayOfYear method of that calendar.

適用対象

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