DateTime.AddDays(Double) DateTime.AddDays(Double) DateTime.AddDays(Double) DateTime.AddDays(Double) Method

定義

このインスタンスの値に、指定された日数を加算した新しい DateTime を返します。Returns a new DateTime that adds the specified number of days to the value of this instance.

public:
 DateTime AddDays(double value);
public DateTime AddDays (double value);
member this.AddDays : double -> DateTime
Public Function AddDays (value As Double) As DateTime

パラメーター

value
Double Double Double Double

整数部と小数部から成る日数。A number of whole and fractional days. value パラメーターは、正または負のどちらの場合もあります。The value parameter can be negative or positive.

戻り値

このインスタンスで表された日付と時刻に value で表された日数を加算した値を保持するオブジェクト。An object whose value is the sum of the date and time represented by this instance and the number of days represented by value.

例外

結果として返された DateTimeMinValue より小さいか、MaxValue より大きいです。The resulting DateTime is less than MinValue or greater than MaxValue.

次の例では、AddDays曜日、週、現在の日付から 36 の日数を調べます。The following example uses the AddDays method to determine the day of the week 36 days after the current date.

using namespace System;

int main()
{
   // Calculate what day of the week is 36 days from this instant.
   DateTime today = System::DateTime::Now;
   DateTime answer = today.AddDays( 36 );
   Console::WriteLine("Today: {0:dddd}", today);
   Console::WriteLine("36 days from today: {0:dddd}", answer);
}
// The example displays output like the following:
//       Today: Wednesday
//       36 days from today: Thursday
using System;

class Class1
{
	static void Main()
	{
		DateTime today = DateTime.Now;
		DateTime answer = today.AddDays(36);
        Console.WriteLine("Today: {0:dddd}", today);
        Console.WriteLine("36 days from today: {0:dddd}", answer);
	}
}
// The example displays output like the following:
//       Today: Wednesday
//       36 days from today: Thursday
Class Class1
   Public Shared Sub Main()
      Dim today As System.DateTime
      Dim answer As System.DateTime

      today = System.DateTime.Now
      answer = today.AddDays(36)

      Console.WriteLine("Today: {0:dddd}", today)
      Console.WriteLine("36 days from today: {0:dddd}", answer)
   End Sub
End Class
' The example displays output like the following:
'       Today: Wednesday
'       36 days from today: Thursday

注釈

このメソッドには、この値は変わりません。DateTimeします。This method does not change the value of this DateTime. 代わりに、新しい返しますDateTime値がこの操作の結果。Instead, it returns a new DateTime whose value is the result of this operation.

小数部valueは 1 日の小数部の一部です。The fractional part of value is the fractional part of a day. たとえば、4.5 は 4 日、12 時間、0 分 0 秒、0 (ミリ秒単位)、および 0 タイマー刻みと同じです。For example, 4.5 is equivalent to 4 days, 12 hours, 0 minutes, 0 seconds, 0 milliseconds, and 0 ticks.

valueパラメーターはミリ秒単位に丸められます。The value parameter is rounded to the nearest millisecond.

AddDaysアカウントうるう年と算術演算のときに日付を実行する月内の日数の数を受け取ります。The AddDays method takes into account leap years and the number of days in a month when performing date arithmetic.

適用対象

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