[Earwig]

Yes... kind of. Per https://en.wikipedia.org/wiki/ISO_8601, there is a "basic format" without separators and an "extended format" that includes them for readability. However, a T is still required to separate the date and time in the most recent version of the standard.

[Groxx]

ISO 8601 is pretty absurd when you actually read it. `2021-W02` and `--01-14` are valid, as is `--1013` (quick! guess what that means! and beware that `-1013` is valid too!)

Please, everyone, use a single format at all times in your systems. I don't really care what it is, though I'm fond of `2021-01-14T06:28:08Z` because it's unambiguous. But don't just say "use ISO 8601", it's far too vague and you'll inevitably have variations.

[gerikson]

Without having read the spec...

* `2021-W02` means the second (ISO) week of 2021. Perfectly valid and used in a lot of planning.

* `--01-14` - I'm assuming this is a recurring date: every 14 Jan for every year

* `--1013` - at 1PM every 10th of the month? Guessing here

I believe ISO 8601 is a ISO codification of a DIN standard, and based on other standards processes I'm guessing some German manufacturing companies were the only ones who bothered showing up, so their internal software practices were encoded into the spec because no-one else cared..

[vianneychevalie]

That is such a common problem when standardizing, I've started to force my clients to have at least one person of each entity in project teams.

Often the biggest entity will end up accidentally forcing their practices, sometimes sub-optimal, to entire organizations, simply by having the manpower to show up to meetings.

[gerikson]

Edit `--1013` is 13 Oct in any year: https://en.wikipedia.org/wiki/ISO_8601#Truncated_representat...

(`--01-14` is Jan 14 in any year, the last dash is "optional").

The "duration" (`P`) and "repetition" (`R`) syntax is also pretty wild.

[JimDabell]

RFC 3339 is a profile of ISO 8601 that is much more limited but still provides the timestamp format everybody expects when you say “ISO 8601”:

https://tools.ietf.org/html/rfc3339

[rakoo]

Indeed, what you really want to say is "use RFC3339" (https://www.ietf.org/rfc/rfc3339.txt)