How can I format DateTime to web UTC format?

Question

I have a DateTime which I want to format to \"2009-09-01T00:00:00.000Z\", but the following code gives me \"2009-09-01T00:00:00.000+01:00\" (both l

Answer 1

Some people have pointed out that ‘ToUniversalTime’ is somewhat unsafe in that it can cause unintended incorrect time dispalys. Expanding on that I’m providing a more detailed example of a solution. The sample here creates an extension to the DateTime object that safely returns a UTC DateTime where you can use ToString as desired….

class Program
{
    static void Main(string[] args)
    {
        DateTime dUtc = new DateTime(2016, 6, 1, 3, 17, 0, 0, DateTimeKind.Utc);
        DateTime dUnspecified = new DateTime(2016, 6, 1, 3, 17, 0, 0, DateTimeKind.Unspecified);

        //Sample of an unintended mangle:
        //Prints "2016-06-01 10:17:00Z"
        Console.WriteLine(dUnspecified.ToUniversalTime().ToString("u"));

        //Prints "2016 - 06 - 01 03:17:00Z"
        Console.WriteLine(dUtc.SafeUniversal().ToString("u"));

        //Prints "2016 - 06 - 01 03:17:00Z"
        Console.WriteLine(dUnspecified.SafeUniversal().ToString("u"));
    }
}

public static class ConvertExtensions
{
    public static DateTime SafeUniversal(this DateTime inTime)
    {
        return (DateTimeKind.Unspecified == inTime.Kind)
            ? new DateTime(inTime.Ticks, DateTimeKind.Utc)
            : inTime.ToUniversalTime();
    }
}