Week numbers in .NET (Legacy)
To get the current ISO 8601 week number in .NET (Legacy), use the following code snippet:
CultureInfo.CurrentCulture.Calendar.GetWeekOfYear(
DateTime.Now,
CalendarWeekRule.FirstFourDayWeek,
DayOfWeek.Monday
);
* Ensure your system or application regional settings are set to follow ISO 8601 standards (weeks start on Monday) if the output varies.