using System;

using System.Globalization;

public class Program

{

    public static void Main()

    {

        string date = "2023-04-26T01:57:40.0000000";

        Console.WriteLine(GetUpdatedDate(date,10));

    }

    public static string GetUpdatedDate(string Date, int days)

        {

        DateTime dateTime = DateTime.ParseExact(Date, "yyyy-MM-ddTHH:mm:ss.fffffff", CultureInfo.InvariantCulture);

        dateTime = dateTime.AddDays(days); 

        return dateTime. ToString( "yyyy-MM-dd") ; 

        }

​

}