ThaiBuddhistCalendar.AddMonths Method

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

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

Namespace: System.Globalization
Assembly: mscorlib (in mscorlib.dll)

Syntax

Public Overrides Function AddMonths ( _
    time As DateTime, _
    months As Integer _
) As DateTime
public override DateTime AddMonths(
    DateTime time,
    int months
)

Parameters

Return Value

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

Exceptions

Exception Condition
ArgumentException

The resulting DateTime is outside the supported range.

ArgumentOutOfRangeException

months is less than -120000.

-or-

months is greater than 120000.

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. This implementation supports only the current era. Therefore, ArgumentException is thrown 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 October, which has 31 days, the specified day is the 31st day of that month, and the value of the months parameter is 6, the resulting year is one more than the specified year, the resulting month is April, and the resulting day is the 30th day, which is the last day in April.

If the value of the months parameter 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.

Examples

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

Imports System.Globalization

Public Class Example
   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      ' Sets a DateTime to April 3, 2002 of the Gregorian calendar.
      Dim myDT As New DateTime(2002, 4, 3, New GregorianCalendar())

      ' Creates an instance of the ThaiBuddhistCalendar.
      Dim myCal As New ThaiBuddhistCalendar()

      ' Displays the values of the DateTime.
      outputBlock.Text += String.Format("April 3, 2002 of the Gregorian calendar equals the following in the ThaiBuddhist calendar:") & vbCrLf
      DisplayValues(outputBlock, myCal, myDT)

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

      ' Displays the values of the DateTime.
      outputBlock.Text &= "After adding two years and ten months:" & vbCrLf
      DisplayValues(outputBlock, myCal, myDT)
   End Sub 

   Public Shared Sub DisplayValues(ByVal outputBlock As System.Windows.Controls.TextBlock, _
                                   ByVal myCal As Calendar, ByVal myDT As DateTime)
      outputBlock.Text += String.Format("   Era:        {0}", myCal.GetEra(myDT)) & vbCrLf
      outputBlock.Text += String.Format("   Year:       {0}", myCal.GetYear(myDT)) & vbCrLf
      outputBlock.Text += String.Format("   Month:      {0}", myCal.GetMonth(myDT)) & vbCrLf
      outputBlock.Text += String.Format("   DayOfYear:  {0}", myCal.GetDayOfYear(myDT)) & vbCrLf
      outputBlock.Text += String.Format("   DayOfMonth: {0}", myCal.GetDayOfMonth(myDT)) & vbCrLf
      outputBlock.Text += String.Format("   DayOfWeek:  {0}", myCal.GetDayOfWeek(myDT)) & vbCrLf
      outputBlock.Text &= vbCrLf
   End Sub 
End Class 
' This example produces the following output.
' April 3, 2002 of the Gregorian calendar equals the following in the ThaiBuddhist calendar:
'    Era:        1
'    Year:       2545
'    Month:      4
'    DayOfYear:  93
'    DayOfMonth: 3
'    DayOfWeek:  Wednesday
' 
' After adding two years and ten months:
'    Era:        1
'    Year:       2548
'    Month:      2
'    DayOfYear:  34
'    DayOfMonth: 3
'    DayOfWeek:  Thursday
using System;
using System.Globalization;


public class Example
{

   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {

      // 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 ThaiBuddhistCalendar.
      ThaiBuddhistCalendar myCal = new ThaiBuddhistCalendar();

      // Displays the values of the DateTime.
      outputBlock.Text += String.Format("April 3, 2002 of the Gregorian calendar equals the following in the ThaiBuddhist calendar:") + "\n";
      DisplayValues(outputBlock, myCal, myDT);

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

      // Displays the values of the DateTime.
      outputBlock.Text += "After adding two years and ten months:" + "\n";
      DisplayValues(outputBlock, myCal, myDT);

   }

   public static void DisplayValues(System.Windows.Controls.TextBlock outputBlock, Calendar myCal, DateTime myDT)
   {
      outputBlock.Text += String.Format("   Era:        {0}", myCal.GetEra(myDT)) + "\n";
      outputBlock.Text += String.Format("   Year:       {0}", myCal.GetYear(myDT)) + "\n";
      outputBlock.Text += String.Format("   Month:      {0}", myCal.GetMonth(myDT)) + "\n";
      outputBlock.Text += String.Format("   DayOfYear:  {0}", myCal.GetDayOfYear(myDT)) + "\n";
      outputBlock.Text += String.Format("   DayOfMonth: {0}", myCal.GetDayOfMonth(myDT)) + "\n";
      outputBlock.Text += String.Format("   DayOfWeek:  {0}", myCal.GetDayOfWeek(myDT)) + "\n";
      outputBlock.Text += "\n";
   }

}

/*
This code produces the following output.

April 3, 2002 of the Gregorian calendar equals the following in the ThaiBuddhist calendar:
   Era:        1
   Year:       2545
   Month:      4
   DayOfYear:  93
   DayOfMonth: 3
   DayOfWeek:  Wednesday

After adding two years and ten months:
   Era:        1
   Year:       2548
   Month:      2
   DayOfYear:  34
   DayOfMonth: 3
   DayOfWeek:  Thursday

*/

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Platforms

Windows Phone

See Also

Reference

ThaiBuddhistCalendar Class

System.Globalization Namespace

System..::.DateTime

AddYears

Calendar..::.AddWeeks

Calendar..::.AddDays

Calendar..::.AddHours

Calendar..::.AddMinutes

Calendar..::.AddSeconds

Calendar..::.AddMilliseconds