At the risk of nitpicking, I prefer RFC 3339, which is a profile of ISO 8601. ISO 8601 provides room for things you typically don't want, e.g. dropping time zone offsets.
While I'm typing this I realise that I've never actually read the ISO 8601 spec, like probably most people here, because it's not free. I cannot even be sure it really exists.
While I'm typing this I realise that I've never actually read the ISO 8601 spec, like probably most people here, because it's not free. I cannot even be sure it really exists.