ISO8601 support when ISO8601DateFormatter Pod is available.
Requires to specify dateFormat=ISO8601 on the attribute's User Info.
https://www.evernote.com/shard/s3/sh/2146a5e0-2440-45ab-9dc8-5f3800d7d1b8/a6fa0ff24d77ca1794a0a842b9f71aab