TIL.
For purposes of this post though, RFC 3339 and ISO8601 are identical. Dates in the format YYYY-MM-DD, so 2024-08-29 is both RFC3339 and ISO8601 compliant.
Not an expert, just spent around 2 minutes looking at https://ijmacd.github.io/rfc3339-iso8601/
Relevant XKCD