using System.Collections;
enum Days1 {Sat, Sun, Mon, Tue, Wed, Thu, Fri};
public static void Main()
var days1 = Enum.GetValues(typeof(Days1))
.Select(v => v.ToString())
var days2 = Enum.GetValues(typeof(Days2))
.Select(v => v.ToString())
var daysIntersect = days1.Intersect(days2).ToList();
Console.WriteLine(string.Join(", ", daysIntersect));