我将使用XmlConvert:

XmlConvert.ToString(DateTime.UtcNow, XmlDateTimeSerializationMode.RoundtripKind);

它会自动保存时区。

如果你在SharePoint 2010或更高版本下开发，你可以使用

using Microsoft.SharePoint;
using Microsoft.SharePoint.Utilities;
...
string strISODate = SPUtility.CreateISO8601DateTimeFromSystemDateTime(DateTime.Now)

我将使用XmlConvert:

XmlConvert.ToString(DateTime.UtcNow, XmlDateTimeSerializationMode.RoundtripKind);

它会自动保存时区。

大多数答案都是毫秒/微秒，这显然是ISO 8601不支持的。正确答案应该是:

System.DateTime.Now.ToString("yyyy-MM-ddTHH:mm:ssK");
// or
System.DateTime.Now.ToUniversalTime().ToString("yyyy-MM-ddTHH:mm:ssK");

引用:

ISO 8601规范 “K”说明符

DateTime.Now.ToString("yyyy-MM-dd'T'HH:mm:ss zzz");

DateTime.Now.ToString("O");

注意:根据您在终端所做的转换，您将使用第一行(最接近它)或第二行。

确保只在本地时间应用格式，因为“zzz”是UTC转换的时区信息。

The "s" standard format specifier represents a custom date and time format string that is defined by the DateTimeFormatInfo.SortableDateTimePattern property. The pattern reflects a defined standard (ISO 8601), and the property is read-only. Therefore, it is always the same, regardless of the culture used or the format provider supplied. The custom format string is "yyyy'-'MM'-'dd'T'HH':'mm':'ss". When this standard format specifier is used, the formatting or parsing operation always uses the invariant culture.

-来自MSDN