GetWeekOfYear varies depending on the FirstDayOfWeek and the CalendarWeekRule used.
Imports System Imports System.Globalization Public Class SamplesCalendar Public Shared Sub Main() Dim myCI As New CultureInfo("en-US") Dim myCal As Calendar = myCI.Calendar Dim myCWR As CalendarWeekRule = myCI.DateTimeFormat.CalendarWeekRule Dim myFirstDOW As DayOfWeek = myCI.DateTimeFormat.FirstDayOfWeek Console.WriteLine(myCal.GetWeekOfYear(DateTime.Now, myCWR, myFirstDOW)) End Sub End Class