using System;

public class Program

{

    public static void Main()

    {

        var timeSpan =    new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc).AddSeconds(1523558027024/1000).ToShortDateString();

​

        Console.WriteLine(timeSpan.ToString());     

    }

​

}

​

​