DateTime.TryParseExact 的结果有 DateTimeKind.Unspecified 尽管输入的日期时间字符串包含时区信息

Question

string dateTimeStr = "2020-01-02T04:00:00Z";
string[] formats = { "yyyy-MM-dd'T'HH:mm:ss'Z'", "yyyy-MM-dd'T'HH:mm:ss.fff'Z'" };

if (DateTime.TryParseExact(dateTimeStr, formats,
                        null,
                        DateTimeStyles.None,
                        out DateTime dateValue))
{
    Console.WriteLine(dateValue.Kind); // why set to DateTimeKind.Unspecified here?
}
else
{
    Console.WriteLine(dateValue);
}

By this documentation :

If s contains time zone information, the time is converted to local time, if necessary, and the Kind property of the returned DateTime object is set to DateTimeKind.Local .

However, in the commented line, the dateValue 's Kind field is set to DateTimeKind.Unspecified , despite the tailing 'Z' in the dateTimeStr to specify its timezone as Utc.

I don't know how it happens and my goad is to have the output DateTime has its Kind set to DateTimeKind.Utc . How could I achieve that?

Answer 1

'Z' is just an escaped literal letter Z that does not mean anything (same for the 'T' ). The time zone specifier in the format string is K .

string[] formats = { "yyyy-MM-ddTHH:mm:ssK", "yyyy-MM-ddTHH:mm:ss.fffK" };

This will give you DateTimeKind.Local like documented, and then you call .ToUniversalTime() on the result to get to the UTC.