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();
    }
}

Answer 2

The best format to use is "yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fffK".

The last K on string will be changed to 'Z' if the date is UTC or with timezone (+-hh:mm) if is local. (http://msdn.microsoft.com/en-us/library/8kb3ffffd4.aspx)

As LukeH said, is good to use the ToUniversalTime if you want that all the dates will be UTC.

The final code is:

string foo = yourDateTime.ToUniversalTime()
                         .ToString("yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fffK");

Answer 3

Try this:

DateTime date = DateTime.ParseExact(
    "Tue, 1 Jan 2008 00:00:00 UTC", 
    "ffffd, d MMM yyyy HH:mm:ss UTC", 
    CultureInfo.InvariantCulture);

Previously asked question

Answer 4

string foo = yourDateTime.ToUniversalTime()
                         .ToString("yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fff'Z'");

Answer 5

You want to use DateTimeOffset class.

var date = new DateTimeOffset(2009, 9, 1, 0, 0, 0, 0, new TimeSpan(0L));
var stringDate = date.ToString("u");

sorry I missed your original formatting with the miliseconds

var stringDate = date.ToString("yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fff'Z'");

Answer 6

This code is working for me:

var datetime = new DateTime(2017, 10, 27, 14, 45, 53, 175, DateTimeKind.Local);
var text = datetime.ToString("o");
Console.WriteLine(text);
--  2017-10-27T14:45:53.1750000+03:00

// datetime from string
var newDate = DateTime.ParseExact(text, "o", null);