This post shows a way to calculate the number of weeks.
Remember that this calculation is culture-dependant
For example the GetWeekOfYear methods requires a criteria to determine
how to determine the first week and which day to consider as FirstDayOfWeek for more info see here:
CalendarWeekRule.FirstDay
Supported by the .NET Compact Framework.
Indicates that the first week of the year starts on the first day of the year and ends before the following designated first day of the week. The value is 0.
CalendarWeekRule.FirstFourDayWeek
Indicates that the first week of the year is the first week with four or more days before the designated first day of the week. The value is 2.
CalendarWeekRule.FirstFullWeek
Indicates that the first week of the year begins on the first occurrence of the designated first day of the week on or after the first day of the year. The value is 1.
Sample Code
Dim x As Date
Dim currentCulture As System.Globalization.CultureInfo
currentCulture = CultureInfo.CurrentCulture
Dim weekNum = currentCulture.Calendar.GetWeekOfYear(x, CalendarWeekRule.FirstFourDayWeek, DayOfWeek.Monday)