using System;

public class Program

{

    public static readonly DateTime UnixEpoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);

    public static void Main()

    {

        Console.WriteLine(new DateTime(2019, 09, 10).Ticks);        

        Console.WriteLine(new DateTime(2019, 08, 05).Ticks);

        Console.WriteLine(new DateTime(637006351778973904));

        long epochTicks = new DateTime(1970, 1, 1).Ticks;

        long unixTime = ((DateTime.UtcNow.Ticks - epochTicks) / TimeSpan.TicksPerSecond) * 1000;

        Console.WriteLine(unixTime);

        Console.WriteLine(FromUnixTime(unixTime / 1000));

    }

    public static DateTime FromUnixTime(long seconds)

        {

            return UnixEpoch.AddSeconds(seconds);

        }

}