Calendar.GetWeekOfYear Method

Parameters

• time
  Type: System.DateTime
  A date and time value.

• rule
  Type: System.Globalization.CalendarWeekRule
  An enumeration value that defines a calendar week.

• firstDayOfWeek
  Type: System.DayOfWeek
  A DayOfWeek value that represents the first day of the week.

Return Value

Type: System.Int32
A positive integer that represents the week of the year that includes the date in the time parameter.

Imports System.Globalization

Module Example
   Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      Dim dfi As DateTimeFormatInfo = DateTimeFormatInfo.CurrentInfo
      Dim date1 As Date = #1/1/2011#
      Dim cal As Calendar = dfi.Calendar

      outputBlock.Text += String.Format("{0:d}: Week {1} ({2})", date1, 
                        cal.GetWeekOfYear(date1, dfi.CalendarWeekRule, 
                                          dfi.FirstDayOfWeek),
                        cal.ToString().Substring(cal.ToString().LastIndexOf(".") + 1)) _  
                        & vbCrLf      
   End Sub
End Module
' The example displays the following output:
'       1/1/2011: Week 1 (GregorianCalendar)

using System;
using System.Globalization;

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      DateTimeFormatInfo dfi = DateTimeFormatInfo.CurrentInfo;
      DateTime date1 = new DateTime(2011, 1, 1);
      Calendar cal = dfi.Calendar;

      outputBlock.Text += String.Format("{0:d}: Week {1} ({2})", date1,
                        cal.GetWeekOfYear(date1, dfi.CalendarWeekRule,
                                          dfi.FirstDayOfWeek),
                        cal.ToString().Substring(cal.ToString().LastIndexOf(".") + 1)) + "\n";
   }
}
// The example displays the following output:
//       1/1/2011: Week 1 (GregorianCalendar)

Imports System.Globalization

Public Class Example

   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)

      ' Gets the Calendar instance associated with a CultureInfo.
      Dim myCI As New CultureInfo("en-US")
      Dim myCal As Calendar = myCI.Calendar

      ' Gets the DTFI properties required by GetWeekOfYear.
      Dim myCWR As CalendarWeekRule = myCI.DateTimeFormat.CalendarWeekRule
      Dim myFirstDOW As DayOfWeek = myCI.DateTimeFormat.FirstDayOfWeek

      ' Displays the number of the current week relative to the beginning of the year.
      outputBlock.Text += String.Format("The CalendarWeekRule used for the en-US culture is {0}.", myCWR) & vbCrLf
      outputBlock.Text += String.Format("The FirstDayOfWeek used for the en-US culture is {0}.", myFirstDOW) & vbCrLf
      outputBlock.Text += String.Format("Therefore, the current week is Week {0} of the current year.", myCal.GetWeekOfYear(DateTime.Now, myCWR, myFirstDOW)) & vbCrLf

      ' Displays the total number of weeks in the current year.
      Dim LastDay = New System.DateTime(DateTime.Now.Year, 12, 31)
      outputBlock.Text += String.Format("There are {0} weeks in the current year ({1}).", myCal.GetWeekOfYear(LastDay, myCWR, myFirstDOW), LastDay.Year) & vbCrLf
   End Sub 'Main 
End Class 'SamplesCalendar


'This code produces the following output.  Results vary depending on the system date.
'
'The CalendarWeekRule used for the en-US culture is FirstDay.
'The FirstDayOfWeek used for the en-US culture is Sunday.
'Therefore, the current week is Week 1 of the current year.
'There are 53 weeks in the current year (2001).

using System;
using System.Globalization;


public class Example
{

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

      // Gets the Calendar instance associated with a CultureInfo.
      CultureInfo myCI = new CultureInfo("en-US");
      Calendar myCal = myCI.Calendar;

      // Gets the DTFI properties required by GetWeekOfYear.
      CalendarWeekRule myCWR = myCI.DateTimeFormat.CalendarWeekRule;
      DayOfWeek myFirstDOW = myCI.DateTimeFormat.FirstDayOfWeek;

      // Displays the number of the current week relative to the beginning of the year.
      outputBlock.Text += String.Format("The CalendarWeekRule used for the en-US culture is {0}.", myCWR) + "\n";
      outputBlock.Text += String.Format("The FirstDayOfWeek used for the en-US culture is {0}.", myFirstDOW) + "\n";
      outputBlock.Text += String.Format("Therefore, the current week is Week {0} of the current year.", myCal.GetWeekOfYear(DateTime.Now, myCWR, myFirstDOW)) + "\n";

      // Displays the total number of weeks in the current year.
      DateTime LastDay = new System.DateTime(DateTime.Now.Year, 12, 31);
      outputBlock.Text += String.Format("There are {0} weeks in the current year ({1}).", myCal.GetWeekOfYear(LastDay, myCWR, myFirstDOW), LastDay.Year) + "\n";

   }

}

/*
This code produces the following output.  Results vary depending on the system date.

The CalendarWeekRule used for the en-US culture is FirstDay.
The FirstDayOfWeek used for the en-US culture is Sunday.
Therefore, the current week is Week 1 of the current year.
There are 53 weeks in the current year (2001).

*/