Lấy các ngày trong tuần sử dụng biến DateTime C#

using System;

class Program
{
    static void Main()
    {
 // Get currrent day of week.
 DayOfWeek today = DateTime.Today.DayOfWeek;
 Console.WriteLine("Today is {0}",
     today);

 // Test current day of week.
 if (today == DayOfWeek.Monday)
 {
     Console.WriteLine("DO WORK");
 }

 // Demonstrate all DayOfWeek values.
 Console.WriteLine("{0}, {1}, {2}, {3}, {4}, {5}, {6}",
     DayOfWeek.Monday,
     DayOfWeek.Tuesday,
     DayOfWeek.Wednesday,
     DayOfWeek.Thursday,
     DayOfWeek.Friday,
     DayOfWeek.Saturday,
     DayOfWeek.Sunday);
    }
}

Output

Today is Monday
DO WORK
Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday