JapaneseCalendar.AddMonths(DateTime, Int32) Method

Definition

Returns a DateTime that is the specified number of months away from the specified DateTime.

public override DateTime AddMonths (DateTime time, int months);

Parameters

time
DateTime

The DateTime to which to add months.

months
Int32

The number of months to add.

Returns

The DateTime that results from adding the specified number of months to the specified DateTime.

Exceptions

The resulting DateTime is outside the supported range.

months is less than -120000.

-or-

months is greater than 120000.

Examples

The following code example displays the values of several components of a DateTime in terms of the Japanese calendar.

using System;
using System.Globalization;

public class SamplesJapaneseCalendar  {

   public static void Main()  {

      // Sets a DateTime to April 3, 2002 of the Gregorian calendar.
      DateTime myDT = new DateTime( 2002, 4, 3, new GregorianCalendar() );

      // Creates an instance of the JapaneseCalendar.
      JapaneseCalendar myCal = new JapaneseCalendar();

      // Displays the values of the DateTime.
      Console.WriteLine( "April 3, 2002 of the Gregorian calendar equals the following in the Japanese calendar:" );
      DisplayValues( myCal, myDT );

      // Adds two years and ten months.
      myDT = myCal.AddYears( myDT, 2 );
      myDT = myCal.AddMonths( myDT, 10 );

      // Displays the values of the DateTime.
      Console.WriteLine( "After adding two years and ten months:" );
      DisplayValues( myCal, myDT );
   }

   public static void DisplayValues( Calendar myCal, DateTime myDT )  {
      Console.WriteLine( "   Era:        {0}", myCal.GetEra( myDT ) );
      Console.WriteLine( "   Year:       {0}", myCal.GetYear( myDT ) );
      Console.WriteLine( "   Month:      {0}", myCal.GetMonth( myDT ) );
      Console.WriteLine( "   DayOfYear:  {0}", myCal.GetDayOfYear( myDT ) );
      Console.WriteLine( "   DayOfMonth: {0}", myCal.GetDayOfMonth( myDT ) );
      Console.WriteLine( "   DayOfWeek:  {0}", myCal.GetDayOfWeek( myDT ) );
      Console.WriteLine();
   }
}

/*
This code produces the following output.

April 3, 2002 of the Gregorian calendar equals the following in the Japanese calendar:
   Era:        4
   Year:       14
   Month:      4
   DayOfYear:  93
   DayOfMonth: 3
   DayOfWeek:  Wednesday

After adding two years and ten months:
   Era:        4
   Year:       17
   Month:      2
   DayOfYear:  34
   DayOfMonth: 3
   DayOfWeek:  Thursday

*/

Remarks

The day part of the resulting DateTime is affected if the resulting day is not a valid day in the resulting month of the resulting year. It is changed to the last valid day in the resulting month of the resulting year. The year part of the resulting DateTime is affected if the resulting month is outside the year of the specified DateTime. The era part of the resulting DateTime is affected if the resulting year is outside the era of the specified DateTime. The time-of-day part of the resulting DateTime remains the same as the specified DateTime.

For example, if the specified month is Juugatsu (October), which has 31 days, the specified day is the 31st day of that month, and months is 6, the resulting year is one more than the specified year, the resulting month is Shigatsu (April), and the resulting day is the 30th day, which is the last day in Shigatsu (April).

If months is negative, the resulting DateTime is earlier than the specified DateTime.

The Kind property of the returned DateTime value always equals DateTimeKind.Unspecified. You can preserve the Kind property of the time parameter by calling the DateTime.SpecifyKind method, as the following example shows.

returnTime = DateTime.SpecifyKind(cal.AddMonths(time, months), time.Kind);

Applies to

Product Versions
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 1.3, 1.4, 1.6, 2.0, 2.1
UWP 10.0

See also