find week ending date of last completed week

Question

For any given date, how would you find the week ending date of the last completed week, if your week runs from Sunday to Saturday?

Answer 1

    public static DateTime EndOfWeek(DateTime dateTime)
    {
        DateTime start = StartOfWeek(dateTime);

        return start.AddDays(6);
    }

    public static DateTime StartOfWeek(DateTime dateTime)
    {
        int days = dateTime.DayOfWeek - DayOfWeek.Monday; 

        if (days < 0) 
            days += 7;

        return dateTime.AddDays(-1 * days).Date;
    }

To find the end of the previous week, just call:

    DateTime endPrevWeek = StartOfWeek(DateTime.Today).AddDays(-1);