Calendar.AddWeeks Method

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

[Visual Basic]
Public Overridable Function AddWeeks( _
   ByVal time As DateTime, _
   ByVal weeks As Integer _
) As DateTime
[C#]
public virtual DateTime AddWeeks(
 DateTime time,
 int weeks
);
[C++]
public: virtual DateTime AddWeeks(
 DateTime time,
 int weeks
);
[JScript]
public function AddWeeks(
   time : DateTime,
 weeks : int
) : DateTime;

Parameters

time

The DateTime to which to add weeks.

weeks

The number of weeks to add.

Return Value

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

Exceptions

Remarks

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

The month part of the resulting DateTime is affected if the resulting day is outside the month of the specified DateTime. 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.

In all .NET Framework classes derived from the Calendar class, a week is defined as seven days.

Example

[Visual Basic, C#, C++] The following code example demonstrates the members of the Calendar class.

[Visual Basic] 
Imports System
Imports System.Globalization


Public Class SamplesCalendar   

   Public Shared Sub Main()

      ' Sets a DateTime to April 3, 2002 of the Gregorian calendar.
      Dim myDT As New DateTime(2002, 4, 3, New GregorianCalendar())

      ' Uses the default calendar of the InvariantCulture.
      Dim myCal As Calendar = CultureInfo.InvariantCulture.Calendar

      ' Displays the values of the DateTime.
      Console.WriteLine("April 3, 2002 of the Gregorian calendar:")
      DisplayValues(myCal, myDT)

      ' Adds 5 to every component of the DateTime.
      myDT = myCal.AddYears(myDT, 5)
      myDT = myCal.AddMonths(myDT, 5)
      myDT = myCal.AddWeeks(myDT, 5)
      myDT = myCal.AddDays(myDT, 5)
      myDT = myCal.AddHours(myDT, 5)
      myDT = myCal.AddMinutes(myDT, 5)
      myDT = myCal.AddSeconds(myDT, 5)
      myDT = myCal.AddMilliseconds(myDT, 5)

      ' Displays the values of the DateTime.
      Console.WriteLine("After adding 5 to each component of the DateTime:")
      DisplayValues(myCal, myDT)

   End Sub 'Main

   Public Shared Sub DisplayValues(myCal As Calendar, myDT As DateTime)
      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("   Hour:         {0}", myCal.GetHour(myDT))
      Console.WriteLine("   Minute:       {0}", myCal.GetMinute(myDT))
      Console.WriteLine("   Second:       {0}", myCal.GetSecond(myDT))
      Console.WriteLine("   Milliseconds: {0}", myCal.GetMilliseconds(myDT))
      Console.WriteLine()
   End Sub 'DisplayValues

End Class 'SamplesCalendar 


'This code produces the following output.

'

'April 3, 2002 of the Gregorian calendar:

'   Era:          1

'   Year:         2002

'   Month:        4

'   DayOfYear:    93

'   DayOfMonth:   3

'   DayOfWeek:    Wednesday

'   Hour:         0

'   Minute:       0

'   Second:       0

'   Milliseconds: 0

'

'After adding 5 to each component of the DateTime:

'   Era:          1

'   Year:         2007

'   Month:        10

'   DayOfYear:    286

'   DayOfMonth:   13

'   DayOfWeek:    Saturday

'   Hour:         5

'   Minute:       5

'   Second:       5

'   Milliseconds: 5

[C#] 
using System;
using System.Globalization;


public class SamplesCalendar  {

   public static void Main()  {

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

      // Uses the default calendar of the InvariantCulture.
      Calendar myCal = CultureInfo.InvariantCulture.Calendar;

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

      // Adds 5 to every component of the DateTime.
      myDT = myCal.AddYears( myDT, 5 );
      myDT = myCal.AddMonths( myDT, 5 );
      myDT = myCal.AddWeeks( myDT, 5 );
      myDT = myCal.AddDays( myDT, 5 );
      myDT = myCal.AddHours( myDT, 5 );
      myDT = myCal.AddMinutes( myDT, 5 );
      myDT = myCal.AddSeconds( myDT, 5 );
      myDT = myCal.AddMilliseconds( myDT, 5 );

      // Displays the values of the DateTime.
      Console.WriteLine( "After adding 5 to each component of the DateTime:" );
      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( "   Hour:         {0}", myCal.GetHour( myDT ) );
      Console.WriteLine( "   Minute:       {0}", myCal.GetMinute( myDT ) );
      Console.WriteLine( "   Second:       {0}", myCal.GetSecond( myDT ) );
      Console.WriteLine( "   Milliseconds: {0}", myCal.GetMilliseconds( myDT ) );
      Console.WriteLine();
   }

}


/*
This code produces the following output.

April 3, 2002 of the Gregorian calendar:
   Era:          1
   Year:         2002
   Month:        4
   DayOfYear:    93
   DayOfMonth:   3
   DayOfWeek:    Wednesday
   Hour:         0
   Minute:       0
   Second:       0
   Milliseconds: 0

After adding 5 to each component of the DateTime:
   Era:          1
   Year:         2007
   Month:        10
   DayOfYear:    286
   DayOfMonth:   13
   DayOfWeek:    Saturday
   Hour:         5
   Minute:       5
   Second:       5
   Milliseconds: 5

*/

[C++] 
#using <mscorlib.dll>
using namespace System;
using namespace System::Globalization;

void DisplayValues(Calendar* myCal, DateTime myDT) {
   Console::WriteLine(S"   Era: {0}", __box(myCal->GetEra(myDT)));
   Console::WriteLine(S"   Year: {0}", __box(myCal->GetYear(myDT)));
   Console::WriteLine(S"   Month: {0}", __box(myCal->GetMonth(myDT)));
   Console::WriteLine(S"   DayOfYear: {0}", __box(myCal->GetDayOfYear(myDT)));
   Console::WriteLine(S"   DayOfMonth: {0}", __box(myCal->GetDayOfMonth(myDT)));
   Console::WriteLine(S"   DayOfWeek: {0}", __box(myCal->GetDayOfWeek(myDT)));
   Console::WriteLine(S"   Hour: {0}", __box(myCal->GetHour(myDT)));
   Console::WriteLine(S"   Minute: {0}", __box(myCal->GetMinute(myDT)));
   Console::WriteLine(S"   Second: {0}", __box(myCal->GetSecond(myDT)));
   Console::WriteLine(S"   Milliseconds: {0}", __box(myCal->GetMilliseconds(myDT)));
   Console::WriteLine();
}

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

   // Uses the default calendar of the InvariantCulture.
   Calendar*  myCal = CultureInfo::InvariantCulture->Calendar;

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

   // Adds 5 to every component of the DateTime.
   myDT = myCal->AddYears(myDT, 5);
   myDT = myCal->AddMonths(myDT, 5);
   myDT = myCal->AddWeeks(myDT, 5);
   myDT = myCal->AddDays(myDT, 5);
   myDT = myCal->AddHours(myDT, 5);
   myDT = myCal->AddMinutes(myDT, 5);
   myDT = myCal->AddSeconds(myDT, 5);
   myDT = myCal->AddMilliseconds(myDT, 5);

   // Displays the values of the DateTime.
   Console::WriteLine(S"After adding 5 to each component of the DateTime:");
   DisplayValues(myCal, myDT);
}

/*
This code produces the following output.

April 3, 2002 of the Gregorian calendar:
Era:          1
Year:         2002
Month:        4
DayOfYear:    93
DayOfMonth:   3
DayOfWeek:    Wednesday
Hour:         0
Minute:       0
Second:       0
Milliseconds: 0

After adding 5 to each component of the DateTime:
Era:          1
Year:         2007
Month:        10
DayOfYear:    286
DayOfMonth:   13
DayOfWeek:    Saturday
Hour:         5
Minute:       5
Second:       5
Milliseconds: 5

*/

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework

See Also

Calendar Class | Calendar Members | System.Globalization Namespace | System.DateTime | AddYears | AddMonths | AddDays | AddHours | AddMinutes | AddSeconds | AddMilliseconds