Given a DateTime object, how do I get an ISO 8601 date in string format?

Question

Given:

DateTime.UtcNow

How do I get a string which represents the same value in an ISO 8601-compliant format?

Note that ISO 8601 de

Answer 1

Use:

private void TimeFormats()
{
    DateTime localTime = DateTime.Now;
    DateTime utcTime = DateTime.UtcNow;
    DateTimeOffset localTimeAndOffset = new DateTimeOffset(localTime, TimeZoneInfo.Local.GetUtcOffset(localTime));

    //UTC
    string strUtcTime_o = utcTime.ToString("o");
    string strUtcTime_s = utcTime.ToString("s");
    string strUtcTime_custom = utcTime.ToString("yyyy-MM-ddTHH:mm:ssK");

    //Local
    string strLocalTimeAndOffset_o = localTimeAndOffset.ToString("o");
    string strLocalTimeAndOffset_s = localTimeAndOffset.ToString("s");
    string strLocalTimeAndOffset_custom = utcTime.ToString("yyyy-MM-ddTHH:mm:ssK");

    //Output
    Response.Write("
UTC
");
    Response.Write("strUtcTime_o: " + strUtcTime_o + "
");
    Response.Write("strUtcTime_s: " + strUtcTime_s + "
");
    Response.Write("strUtcTime_custom: " + strUtcTime_custom + "
");

    Response.Write("
Local Time
");
    Response.Write("strLocalTimeAndOffset_o: " + strLocalTimeAndOffset_o + "
");
    Response.Write("strLocalTimeAndOffset_s: " + strLocalTimeAndOffset_s + "
");
    Response.Write("strLocalTimeAndOffset_custom: " + strLocalTimeAndOffset_custom + "
");

}

OUTPUT

UTC
    strUtcTime_o: 2012-09-17T22:02:51.4021600Z
    strUtcTime_s: 2012-09-17T22:02:51
    strUtcTime_custom: 2012-09-17T22:02:51Z

Local Time
    strLocalTimeAndOffset_o: 2012-09-17T15:02:51.4021600-07:00
    strLocalTimeAndOffset_s: 2012-09-17T15:02:51
    strLocalTimeAndOffset_custom: 2012-09-17T22:02:51Z

Sources:

• Standard Date and Time Format Strings (MSDN)

• Custom Date and Time Format Strings (MSDN)