How to get the day name from a selected date?

I have this : Datetime.Now(); or 23/10/2009
I want this : Friday

For local date-time (GMT-5) and using Gregorian calendar.

//default locale
System.DateTime.Now.DayOfWeek.ToString();
//localized version
System.DateTime.Now.ToString("dddd");

To make the answer more complete:

• DayOfWeek MSDN article

• If localization is important, you should use the "dddd" string format as Fredrik pointed out - MSDN "dddd" format article

If you want to know the day of the week for your code to do something with it, DateTime.Now.DayOfWeek will do the job.

If you want to display the day of week to the user, DateTime.Now.ToString("dddd") will give you the localized day name, according to the current culture (MSDN info on the "dddd" format string).

System.Threading.Thread.CurrentThread.CurrentUICulture.DateTimeFormat.GetDayName(System.DateTime.Now.DayOfWeek)

or

System.Threading.Thread.CurrentThread.CurrentUICulture.DateTimeFormat.GetDayName(DateTime.Parse("23/10/2009").DayOfWeek)

DateTime.Now.DayOfWeek quite easy to guess actually.

for any given date:

   DateTime dt = //....
   DayOfWeek dow = dt.DayOfWeek; //enum
   string str = dow.ToString(); //string

DateTime now = DateTime.Now
string s = now.DayOfWeek.ToString();

try this:

DateTime.Now.DayOfWeek

Here is more simple

DateTime dt;
string yourdate = dt.DayOfWeek.ToString()

better than declare redundant DayOfWeek

You're looking for the DayOfWeek property.

Here's the msdn article.

What about if we use String.Format here

DateTime today = DateTime.Today;
String.Format("{0:dd-MM}, {1:dddd}", today, today) //In dd-MM format
String.Format("{0:MM-dd}, {1:dddd}", today, today) //In MM-dd format

(DateTime.Parse((Eval("date").ToString()))).DayOfWeek.ToString()

at the place of Eval("date"),you can use any date...get name of day

I use this Extension Method:

public static string GetDayName(this DateTime date)
{
	string _ret = string.Empty; //Only for .NET Framework 4++
	var culture = new System.Globalization.CultureInfo("es-419"); //<- 'es-419' = Spanish (Latin America), 'en-US' = English (United States)
	_ret = culture.DateTimeFormat.GetDayName(date.DayOfWeek); //<- Get the Name 	
	_ret = culture.TextInfo.ToTitleCase(_ret.ToLower()); //<- Convert to Capital title
	return _ret;
}

        Random Rnd = new Random();
        RandomDates Rdate = new RandomDates();
        PaymentDetails Payd = new PaymentDetails();
        DayOfWeek strDay = DateTime.Today.DayOfWeek;
        var dateTime = DateTime.Now;
        var dateValue2 = dateTime.ToString(@"MM\/dd\/yyyy");


        StepDescription = "Fill MatterInformation. ";

        
       

            Console.Write(" Input the Day : ");
            dt = Convert.ToInt32(Console.ReadLine());
            Console.Write(" Input the Month : ");
            mn = Convert.ToInt32(Console.ReadLine());
            Console.Write(" Input the Year : ");
            yr = Convert.ToInt32(Console.ReadLine());
            DateTime d = new DateTime(2021, 04, yr);
            var culture = System.Threading.Thread.CurrentThread.CurrentCulture;
            var diff = d.DayOfWeek - culture.DateTimeFormat.FirstDayOfWeek;
            if (diff < 0)
                diff += 7;
            var x = d.AddDays(-diff).Date;


            dateTime = DateTime.Now;
            dateValue2 = dateTime.ToString(@"MM\/dd\/yyyy");
            Console.WriteLine($"Date Value: {dateValue2}");

           // strDay = 

        }
        if (!strDay.Equals("Sunday") | !strDay.Equals("Saturday"))
        {
            Console.WriteLine("___________________OK____________________________________________");
            // string NotificateionDate = Rdate.DateWithin_PastDays(Rnd.Next(30, 260)).ToString(@"MM\/dd\/yyyy");

            // CustomLibrary.seWaitUntilElementIsVisible(10, NotiFiedDateTab.Actions.seGetLocator(), "NotiFiedDateTab");
            NotiFiedDateTab.Actions.Set(ControlPropertyNames.Text, dateValue2);

        }
        else
        {
            Console.WriteLine("_________________________NOT______________________________________");
            if (strDay.Equals("Sunday"))
            {
                dateTime = dateTime.AddDays(-2);
                dateValue2 = dateTime.ToString(@"MM\/dd\/yyyy");
                NotiFiedDateTab.Actions.Set(ControlPropertyNames.Text, dateValue2);
            }
            else if (strDay.Equals("Saturday"))
            {

                dateTime = dateTime.AddDays(-1);
                dateValue2 = dateTime.ToString(@"MM\/dd\/yyyy");
                NotiFiedDateTab.Actions.Set(ControlPropertyNames.Text, dateValue2);
            }
        }
      
    }

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace GuessTheDay
{
class Program
{
    static void Main(string[] args)
    { 
 Console.WriteLine("Enter the Day Number ");
 int day = int.Parse(Console.ReadLine());
 Console.WriteLine(" Enter The Month");
int month = int.Parse(Console.ReadLine());
Console.WriteLine("Enter Year ");
int year = int.Parse(Console.ReadLine());
DateTime mydate = new DateTime(year,month,day);
string formatteddate = string.Format("{0:dddd}", mydate);
Console.WriteLine("The day should be " + formatteddate);
}  
 } 
   }