我如何parsing和转换DateTime的RFC 3339date时间格式？
如何将DateTime结构转换为其等效的RFC 3339格式的string表示forms和/或将此string表示formsparsing为DateTime结构？ RFC-3339date – 时间格式用于许多规范，如Atom Syndication Format 。
您不需要编写自己的转换代码。 只是使用
XmlConvert.ToDateTime(string s, XmlDateTimeSerializationMode dateTimeOption) parsing一个RFC-3339string，和
XmlConvert.ToString(DateTime value, XmlDateTimeSerializationMode dateTimeOption)
将（UTC）date时间转换为string。
参考。
http://msdn.microsoft.com/en-us/library/ms162342(v=vs.110).aspx
http://msdn.microsoft.com/en-us/library/ms162344(v=vs.110).aspx
这是一个在C＃中的实现，如何parsing和转换date时间的RFC-3339表示。 唯一的限制是DateTime在协调世界时（UTC）。
using System; using System.Globalization; namespace DateTimeConsoleApplication { /// <summary> /// Provides methods for converting <see cref="DateTime"/> structures to and from the equivalent RFC 3339 string representation. /// </summary> public static class Rfc3339DateTime { //============================================================ // Private members //============================================================ #region Private Members /// <summary> /// Private member to hold array of formats that RFC 3339 date-time representations conform to. /// </summary> private static string[] formats = new string[0]; /// <summary> /// Private member to hold the DateTime format string for representing a DateTime in the RFC 3339 format. /// </summary> private const string format = "yyyy-MM-dd'T'HH:mm:ss.fffK"; #endregion //============================================================ // Public Properties //============================================================ #region Rfc3339DateTimeFormat /// <summary> /// Gets the custom format specifier that may be used to represent a <see cref="DateTime"/> in the RFC 3339 format. /// </summary> /// <value>A <i>DateTime format string</i> that may be used to represent a <see cref="DateTime"/> in the RFC 3339 format.</value> /// <remarks> /// <para> /// This method returns a string representation of a <see cref="DateTime"/> that /// is precise to the three most significant digits of the seconds fraction; that is, it represents /// the milliseconds in a date and time value. The <see cref="Rfc3339DateTimeFormat"/> is a valid /// date-time format string for use in the <see cref="DateTime.ToString(String, IFormatProvider)"/> method. /// </para> /// </remarks> public static string Rfc3339DateTimeFormat { get { return format; } } #endregion #region Rfc3339DateTimePatterns /// <summary> /// Gets an array of the expected formats for RFC 3339 date-time string representations. /// </summary> /// <value> /// An array of the expected formats for RFC 3339 date-time string representations /// that may used in the <see cref="DateTime.TryParseExact(String, string[], IFormatProvider, DateTimeStyles, out DateTime)"/> method. /// </value> public static string[] Rfc3339DateTimePatterns { get { if (formats.Length > 0) { return formats; } else { formats = new string[11]; // Rfc3339DateTimePatterns formats[0] = "yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fffffffK"; formats[1] = "yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'ffffffK"; formats[2] = "yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fffffK"; formats[3] = "yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'ffffK"; formats[4] = "yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fffK"; formats[5] = "yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'ffK"; formats[6] = "yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fK"; formats[7] = "yyyy'-'MM'-'dd'T'HH':'mm':'ssK"; // Fall back patterns formats[8] = "yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fffffffK"; // RoundtripDateTimePattern formats[9] = DateTimeFormatInfo.InvariantInfo.UniversalSortableDateTimePattern; formats[10] = DateTimeFormatInfo.InvariantInfo.SortableDateTimePattern; return formats; } } } #endregion //============================================================ // Public Methods //============================================================ #region Parse(string s) /// <summary> /// Converts the specified string representation of a date and time to its <see cref="DateTime"/> equivalent. /// </summary> /// <param name="s">A string containing a date and time to convert.</param> /// <returns>A <see cref="DateTime"/> equivalent to the date and time contained in <paramref name="s"/>.</returns> /// <remarks> /// The string <paramref name="s"/> is parsed using formatting information in the <see cref="DateTimeFormatInfo.InvariantInfo"/> object. /// </remarks> /// <exception cref="ArgumentNullException"><paramref name="s"/> is a <b>null</b> reference (Nothing in Visual Basic).</exception> /// <exception cref="FormatException"><paramref name="s"/> does not contain a valid RFC 3339 string representation of a date and time.</exception> public static DateTime Parse(string s) { //------------------------------------------------------------ // Validate parameter //------------------------------------------------------------ if(s == null) { throw new ArgumentNullException("s"); } DateTime result; if (Rfc3339DateTime.TryParse(s, out result)) { return result; } else { throw new FormatException(String.Format(null, "{0} is not a valid RFC 3339 string representation of a date and time.", s)); } } #endregion #region ToString(DateTime utcDateTime) /// <summary> /// Converts the value of the specified <see cref="DateTime"/> object to its equivalent string representation. /// </summary> /// <param name="utcDateTime">The Coordinated Universal Time (UTC) <see cref="DateTime"/> to convert.</param> /// <returns>A RFC 3339 string representation of the value of the <paramref name="utcDateTime"/>.</returns> /// <remarks> /// <para> /// This method returns a string representation of the <paramref name="utcDateTime"/> that /// is precise to the three most significant digits of the seconds fraction; that is, it represents /// the milliseconds in a date and time value. /// </para> /// <para> /// While it is possible to display higher precision fractions of a second component of a time value, /// that value may not be meaningful. The precision of date and time values depends on the resolution /// of the system clock. On Windows NT 3.5 and later, and Windows Vista operating systems, the clock's /// resolution is approximately 10-15 milliseconds. /// </para> /// </remarks> /// <exception cref="ArgumentException">The specified <paramref name="utcDateTime"/> object does not represent a <see cref="DateTimeKind.Utc">Coordinated Universal Time (UTC)</see> value.</exception> public static string ToString(DateTime utcDateTime) { if (utcDateTime.Kind != DateTimeKind.Utc) { throw new ArgumentException("utcDateTime"); } return utcDateTime.ToString(Rfc3339DateTime.Rfc3339DateTimeFormat, DateTimeFormatInfo.InvariantInfo); } #endregion #region TryParse(string s, out DateTime result) /// <summary> /// Converts the specified string representation of a date and time to its <see cref="DateTime"/> equivalent. /// </summary> /// <param name="s">A string containing a date and time to convert.</param> /// <param name="result"> /// When this method returns, contains the <see cref="DateTime"/> value equivalent to the date and time /// contained in <paramref name="s"/>, if the conversion succeeded, /// or <see cref="DateTime.MinValue">MinValue</see> if the conversion failed. /// The conversion fails if the s parameter is a <b>null</b> reference (Nothing in Visual Basic), /// or does not contain a valid string representation of a date and time. /// This parameter is passed uninitialized. /// </param> /// <returns><b>true</b> if the <paramref name="s"/> parameter was converted successfully; otherwise, <b>false</b>.</returns> /// <remarks> /// The string <paramref name="s"/> is parsed using formatting information in the <see cref="DateTimeFormatInfo.InvariantInfo"/> object. /// </remarks> public static bool TryParse(string s, out DateTime result) { //------------------------------------------------------------ // Attempt to convert string representation //------------------------------------------------------------ bool wasConverted = false; result = DateTime.MinValue; if (!String.IsNullOrEmpty(s)) { DateTime parseResult; if (DateTime.TryParseExact(s, Rfc3339DateTime.Rfc3339DateTimePatterns, DateTimeFormatInfo.InvariantInfo, DateTimeStyles.AdjustToUniversal, out parseResult)) { result = DateTime.SpecifyKind(parseResult, DateTimeKind.Utc); wasConverted = true; } } return wasConverted; } #endregion } }
在.NET中（假设UTC）：
datetime.ToString("YYYY-MM-DD'T'HH:mm:ssZ")
DateTime.Parse()可以用来转换回DateTime结构。
一个简单的公式就可以得到你以后的结果：
rfcFormat = DateDiff("s", "1/1/1970", Now())
