by micah.stetson:

Time.Parse() doesn't understand the full ISO 8601 grammar.  That's sensible, but not
clearly 
documented.  Instead, time.ISO8601 chooses one of the many formats allowed by ISO 8601.  
Almost.  If the errata[1] for RFC 3339[2] are correct, then time.ISO8601 may not be
allowed by ISO 
8601 because it mixes a "basic format" (no colon) time zone offset with
"extended format" 
(hyphens and colons) time and date specifications.

Since stdISO8601TZ doesn't allow a colon, there's currently no way to parse dates
formatted 
according to RFC 3339 or the W3C Note[3] on the subject.

[1] http://www.rfc-editor.org/errata_search.php?rfc=3339
[2] http://tools.ietf.org/html/rfc3339
[3] http://www.w3.org/TR/NOTE-datetime

I think the main difficulty in fixing this is just determining which format strings
should be used 
for the different time zone formats and which format time.ISO8601 should use.

I suggest the following:

    stdNumTZ = "-0700" // always numeric
    stdNumColonTZ = "-07:00" // always numeric
    stdISO8601TZB = "ZB" // ISO8601 "basic" i.e. Z or -0700, RFC822
    stdISO8601TZX = "ZX" // ISO8601 "extended" i.e. Z or -07:00, RFC3339

    ISO8601 = "20060102T150405ZB" // as used by Google Calendar
    RFC3339 = "2006-01-02T15:04:05ZX"
    OldISO8601 = "2006-01-02T15:04:05ZB" // what Go uses today

Existing uses of time.ISO8601 could be changed to time.OldISO8601 using gofmt.

If this looks good, I'm willing to do the code changes.