问题
ISO 8601 and RFC 3339 seem to be two formats that are common the web. Should I use one over the other? Is one just an extension? Do I really need to care that bad?
回答1:
Is one just an extension?
Pretty much, yes - RFC 3339 is listed as a profile of ISO 8601. Most notably RFC 3339 specifies a complete representation of date and time (only fractional seconds are optional). The RFC also has some small, subtle differences. For example truncated representations of years with only two digits are not allowed -- RFC 3339 requires 4-digit years, and the RFC only allows a period character to be used as the decimal point for fractional seconds. The RFC also allows the "T" to be replaced by a space (or other character), while the standard only allows it to be omitted (and only when there is agreement between all parties using the representation).
I wouldn't worry too much about the differences between the two, but on the off-chance your use case runs in to them, it'd be worth your while taking a glance at:
- RFC 3339
- Wikipedia entry on ISO 8601
回答2:
RFC 3339 is mostly a profile of ISO 8601, but is actually inconsistent with it in borrowing the "-00:00" timezone specification from RFC 2822. This is described in the Wikipedia article.
回答3:
You shouldn't have to care that much. RFC 3339, according to itself, is a set of standards derived from ISO 8601. There's quite a few minute differences though, and they're all outlined in RFC 3339. I could go through them all here, but you'd probably do better just reading the document for yourself in the event you're worried:
http://www.ietf.org/rfc/rfc3339.txt
来源：https://stackoverflow.com/questions/522251/whats-the-difference-between-iso-8601-and-rfc-3339-date-formats