using System;

using NodaTime;

public class Program

{

    public static void Main()

    {

        LocalDate now = LocalDate.FromDateTime(DateTime.Now);

        LocalDate? d1 = null;

        LocalDate? d2 = LocalDate.Subtract(now, Period.FromDays(3));

        var a = LocalDateTime.FromDateTime(DateTime.Now);

        var d3 = new OffsetDateTime(LocalDateTime.FromDateTime(DateTime.Now), Offset.Zero);

        var d4 = new OffsetDateTime(LocalDateTime.FromDateTime(DateTime.Now), Offset.FromHours(-4));

        var d5 = new OffsetDateTime(LocalDateTime.FromDateTime(DateTime.Now), Offset.FromHours(3));

        var i = 0;

        Console.WriteLine($"{++i}: {a}");

        Console.WriteLine($"{++i}: {a.ToString("s", System.Globalization.CultureInfo.InvariantCulture)} - {System.Uri.EscapeDataString(a.ToString("s", System.Globalization.CultureInfo.InvariantCulture))}");

        Console.WriteLine($"{++i}: {d1}");

        Console.WriteLine($"{++i}: {d2}");

        Console.WriteLine($"{++i}: {d3.ToString("uuuu'-'MM'-'dd'T'HH':'mm':'sso<G>", System.Globalization.CultureInfo.InvariantCulture)} - {System.Uri.EscapeDataString(d3.ToString("uuuu'-'MM'-'dd'T'HH':'mm':'sso<G>", System.Globalization.CultureInfo.InvariantCulture))}");

        Console.WriteLine($"{++i}: {d3.ToString("uuuu'-'MM'-'dd'T'HH':'mm':'sso<+HH:mm>", System.Globalization.CultureInfo.InvariantCulture)} - {System.Uri.EscapeDataString(d3.ToString("uuuu'-'MM'-'dd'T'HH':'mm':'sso<+HH:mm>", System.Globalization.CultureInfo.InvariantCulture))}");

        Console.WriteLine($"{++i}: {d3.ToString("G", System.Globalization.CultureInfo.InvariantCulture)} - {System.Uri.EscapeDataString(d3.ToString("G", System.Globalization.CultureInfo.InvariantCulture))}");

        Console.WriteLine($"{++i}: {d4.ToString("uuuu'-'MM'-'dd'T'HH':'mm':'sso<G>", System.Globalization.CultureInfo.InvariantCulture)} - {System.Uri.EscapeDataString(d4.ToString("uuuu'-'MM'-'dd'T'HH':'mm':'sso<G>", System.Globalization.CultureInfo.InvariantCulture))}");

        Console.WriteLine($"{++i}: {d4.ToString("uuuu'-'MM'-'dd'T'HH':'mm':'sso<+HH:mm>", System.Globalization.CultureInfo.InvariantCulture)} - {System.Uri.EscapeDataString(d4.ToString("uuuu'-'MM'-'dd'T'HH':'mm':'sso<+HH:mm>", System.Globalization.CultureInfo.InvariantCulture))}");

        Console.WriteLine($"{++i}: {d4.ToString("G", System.Globalization.CultureInfo.InvariantCulture)} - {System.Uri.EscapeDataString(d4.ToString("G", System.Globalization.CultureInfo.InvariantCulture))}");

        Console.WriteLine($"{++i}: {d5.ToString("uuuu'-'MM'-'dd'T'HH':'mm':'sso<G>", System.Globalization.CultureInfo.InvariantCulture)} - {System.Uri.EscapeDataString(d5.ToString("uuuu'-'MM'-'dd'T'HH':'mm':'sso<G>", System.Globalization.CultureInfo.InvariantCulture))}");

        Console.WriteLine($"{++i}: {d5.ToString("uuuu'-'MM'-'dd'T'HH':'mm':'sso<+HH:mm>", System.Globalization.CultureInfo.InvariantCulture)} - {System.Uri.EscapeDataString(d5.ToString("uuuu'-'MM'-'dd'T'HH':'mm':'sso<+HH:mm>", System.Globalization.CultureInfo.InvariantCulture))}");

        Console.WriteLine($"{++i}: {d5.ToString("G", System.Globalization.CultureInfo.InvariantCulture)} - {System.Uri.EscapeDataString(d5.ToString("G", System.Globalization.CultureInfo.InvariantCulture))}");

        Console.WriteLine($"{++i}: {DateTime.Now.ToString("s")}");

    }

}

​