public static bool Contains(this Week week, DayOfWeek day) => week.HasFlag(day.Convert());
public static bool Contains(this Week week, DayOfWeek day) => week.HasFlag(day.Convert());
public static bool Contains(this Week week, DayOfWeek day) => week.HasFlag(day.Convert());
public static bool Contains(this Week week, DayOfWeek day) => week.HasFlag(day.Convert());