給定一個 DateTime 對象，如何獲取字符串格式的 ISO 8601 日期？ (Given a DateTime object, how do I get an ISO 8601 date in string format?)

問題描述

給定一個 DateTime 對象，如何獲取字符串格式的 ISO 8601 日期？ (Given a DateTime object, how do I get an ISO 8601 date in string format?)

給定：

DateTime.UtcNow

如何在 符合 ISO 8601 的格式？

請注意，ISO 8601 定義了許多類似的格式。我要找的具體格式是：

yyyy‑MM‑ddTHH:mm:ssZ

參考解法

方法 1:

Note to readers: Several commenters have pointed out some problems in this answer (related particularly to the first suggestion). Refer to the comments section for more information.

DateTime.UtcNow.ToString("yyyy‑MM‑ddTHH\\:mm\\:ss.fffffffzzz", CultureInfo.InvariantCulture);

Using custom date‑time formatting, this gives you a date similar to
2008‑09‑22T13:57:31.2311892‑04:00.

Another way is:

DateTime.UtcNow.ToString("o", CultureInfo.InvariantCulture);

which uses the standard "round‑trip" style (ISO 8601) to give you
2008‑09‑22T14:01:54.9571247Z.

To get the specified format, you can use:

DateTime.UtcNow.ToString("yyyy‑MM‑ddTHH:mm:ssZ", CultureInfo.InvariantCulture)

方法 2:

DateTime.UtcNow.ToString("s", System.Globalization.CultureInfo.InvariantCulture) should give you what you are looking for as the "s" format specifier is described as a sortable date/time pattern; conforms to ISO 8601.

EDIT: To get the additional Z at the end as the OP requires, use "o" instead of "s".

方法 3:

DateTime.UtcNow.ToString("s")

Returns something like 2008‑04‑10T06:30:00

UtcNow obviously returns a UTC time so there is no harm in:

string.Concat(DateTime.UtcNow.ToString("s"), "Z")

方法 4:

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("<br/>UTC<br/>");
    Response.Write("strUtcTime_o: " + strUtcTime_o + "<br/>");
    Response.Write("strUtcTime_s: " + strUtcTime_s + "<br/>");
    Response.Write("strUtcTime_custom: " + strUtcTime_custom + "<br/>");

    Response.Write("<br/>Local Time<br/>");
    Response.Write("strLocalTimeAndOffset_o: " + strLocalTimeAndOffset_o + "<br/>");
    Response.Write("strLocalTimeAndOffset_s: " + strLocalTimeAndOffset_s + "<br/>");
    Response.Write("strLocalTimeAndOffset_custom: " + strLocalTimeAndOffset_custom + "<br/>");

}

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)

方法 5:

System.DateTime.UtcNow.ToString("o")

=>

val it : string = "2013‑10‑13T13:03:50.2950037Z"

(by Iain、Wayne、Simon Wilson、Iain、Don、Henrik)

參考文件

1. Given a DateTime object, how do I get an ISO 8601 date in string format? (CC BY‑SA 2.5/3.0/4.0)