using System.Globalization;
public static void Main()
Console.WriteLine(GetFirstDayOfWeekByCulture("en"));
Console.WriteLine(GetFirstDayOfWeekByCulture("en-US"));
Console.WriteLine(GetFirstDayOfWeekByCulture("US"));
Console.WriteLine(GetFirstDayOfWeekByCulture("de"));
Console.WriteLine(GetFirstDayOfWeekByCulture("de-AT"));
Console.WriteLine(GetFirstDayOfWeekByCulture("AT"));
Console.WriteLine(GetFirstDayOfWeekByCulture(""));
public static DayOfWeek GetFirstDayOfWeekByCulture(string cultureName)
return new CultureInfo(cultureName).DateTimeFormat.FirstDayOfWeek;