UmAlQuraCalendar.AddMonths(DateTime, Int32) Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Calculates a date that is a specified number of months away from a specified initial date.
public:
override DateTime AddMonths(DateTime time, int months);public override DateTime AddMonths (DateTime time, int months);override this.AddMonths : DateTime * int -> DateTimePublic Overrides Function AddMonths (time As DateTime, months As Integer) As DateTimeParameters
- time
- DateTime
The date to which to add months. The UmAlQuraCalendar class supports only dates from 04/30/1900 00.00.00 (Gregorian date) through 11/16/2077 23:59:59 (Gregorian date).
- months
- Int32
The positive or negative number of months to add.
Returns
The date yielded by adding the number of months specified by the months parameter to the date specified by the time parameter.
Exceptions
The resulting date is outside the range supported by the UmAlQuraCalendar class.
months is less than -120,000 or greater than 120,000.
-or-
time is outside the range supported by this calendar.
Examples
The following example instantiates a DateTime value and displays the values of several of its components in the Um Al Qura calendar. Next, it calls the AddYears and AddMonths methods to add 2 years and 10 months in the Um Al Qura calendar to the date value. Finally, it again displays the values of these date components in the Um Al Qura calendar.
using System;
using System.Globalization;
public class Example
{
public static void Main()
{
DateTime date1 = new DateTime(2011, 4, 3, new GregorianCalendar());
Calendar cal = new UmAlQuraCalendar();
Console.WriteLine("{0:MMMM d, yyyy} in the Gregorian calendar is equivalent to:", date1);
DisplayCalendarInfo(cal, date1);
// Add 2 years and 10 months by calling UmAlQuraCalendar methods.
date1 = cal.AddYears(date1, 2);
date1 = cal.AddMonths(date1, 10);
Console.WriteLine("After adding 2 years and 10 months in the {0} calendar,",
GetCalendarName(cal));
Console.WriteLine("{0:MMMM d, yyyy} in the Gregorian calendar is equivalent to:", date1);
DisplayCalendarInfo(cal, date1);
}
private static void DisplayCalendarInfo(Calendar cal, DateTime date1)
{
Console.WriteLine(" Calendar: {0}", GetCalendarName(cal));
Console.WriteLine(" Era: {0}", cal.GetEra(date1));
Console.WriteLine(" Year: {0}", cal.GetYear(date1));
Console.WriteLine(" Month: {0}", cal.GetMonth(date1));
Console.WriteLine(" DayOfYear: {0}", cal.GetDayOfYear(date1));
Console.WriteLine(" DayOfMonth: {0}", cal.GetDayOfMonth(date1));
Console.WriteLine(" DayOfWeek: {0}\n", cal.GetDayOfWeek(date1));
}
private static string GetCalendarName(Calendar cal)
{
return cal.ToString().Replace("System.Globalization.", "").
Replace("Calendar", "");
}
}
// The example displays the following output:
// April 3, 2011 in the Gregorian calendar is equivalent to:
// Calendar: UmAlQura
// Era: 1
// Year: 1432
// Month: 4
// DayOfYear: 118
// DayOfMonth: 29
// DayOfWeek: Sunday
//
// After adding 2 years and 10 months in the UmAlQura calendar,
// January 1, 2014 in the Gregorian calendar is equivalent to:
// Calendar: UmAlQura
// Era: 1
// Year: 1435
// Month: 2
// DayOfYear: 59
// DayOfMonth: 29
// DayOfWeek: Wednesday
Imports System.Globalization
Module Example
Public Sub Main()
Dim date1 As Date = New Date(2011, 4, 3, New GregorianCalendar())
Dim cal As New UmAlQuraCalendar()
Console.WriteLine("{0:MMMM d, yyyy} in the Gregorian calendar is equivalent to:", date1)
DisplayCalendarInfo(cal, date1)
' Add 2 years and 10 months by calling UmAlQuraCalendar methods.
date1 = cal.AddYears(date1, 2)
date1 = cal.AddMonths(date1, 10)
Console.WriteLine("After adding 2 years and 10 months in the {0} calendar,",
GetCalendarName(cal))
Console.WriteLine("{0:MMMM d, yyyy} in the Gregorian calendar is equivalent to:", date1)
DisplayCalendarInfo(cal, date1)
End Sub
Private Sub DisplayCalendarInfo(cal As Calendar, date1 As Date)
Console.WriteLine(" Calendar: {0}", GetCalendarName(cal))
Console.WriteLine(" Era: {0}", cal.GetEra(date1))
Console.WriteLine(" Year: {0}", cal.GetYear(date1))
Console.WriteLine(" Month: {0}", cal.GetMonth(date1))
Console.WriteLine(" DayOfYear: {0}", cal.GetDayOfYear(date1))
Console.WriteLine(" DayOfMonth: {0}", cal.GetDayOfMonth(date1))
Console.WriteLine(" DayOfWeek: {0}", cal.GetDayOfWeek(date1))
Console.WriteLine()
End Sub
Private Function GetCalendarName(cal As Calendar) As String
Return cal.ToString().Replace("System.Globalization.", "").
Replace("Calendar", "")
End Function
End Module
' The example displays the following output:
' April 3, 2011 in the Gregorian calendar is equivalent to:
' Calendar: UmAlQura
' Era: 1
' Year: 1432
' Month: 4
' DayOfYear: 118
' DayOfMonth: 29
' DayOfWeek: Sunday
'
' After adding 2 years and 10 months in the UmAlQura calendar,
' January 1, 2014 in the Gregorian calendar is equivalent to:
' Calendar: UmAlQura
' Era: 1
' Year: 1435
' Month: 2
' DayOfYear: 59
' DayOfMonth: 29
' DayOfWeek: Wednesday
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, an exception 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 Zulkadah, which has 30 days, the specified day is the 30th day of that month, and the value of the months parameter is 3, the resulting year is one more than the specified year, the resulting month is Safar, and the resulting day is the 29th day, which is the last day in Safar.
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.
returnTime = DateTime.SpecifyKind(cal.AddMonths(time, months), time.Kind);
returnTime = DateTime.SpecifyKind(cal.AddMonths(time, months), time.Kind)
