DateTime.Now.DayOfWeek.ToString() with CultureInfo

var culture = new System.Globalization.CultureInfo("de-DE");
var day = culture.DateTimeFormat.GetDayName(DateTime.Today.DayOfWeek);

You can use the DateTimeFormat.DayNames property of the german CultureInfo. For example:

CultureInfo german = new CultureInfo("de-DE");
string sunday = german.DateTimeFormat.DayNames[(int)DayOfWeek.Sunday];

This is the solution in Visual Basic

Dim GermanCultureInfo As Globalization.CultureInfo = New Globalization.CultureInfo("de-DE")

Return GermanCultureInfo.DateTimeFormat.GetDayName(DayOfWeek.Sunday)

The function of the solution is Obsolete by the way DateTime.Now.ToString("dddd", new System.Globalization.CultureInfo("de-DE"))