To be fair, proper ISO 8601 specifies hyphens as the separator between date elements, and I don’t think I’ve ever seen a XXXX-XX-XX (with hyphens) be used for YYYY-DD-MM. Just XX-XX could perhaps be ambiguous, but fortunately that’s not allowed by the standard, and anyone using just year-day for XXXX-XX is absolutely trolling. YYYY-DDD could have a use, though should really use a separate separator to not sort together IMO. A year-week designation could possibly look like XXXX-XX, but that seems unlikely to just be dropped in that format without context, at least to my western US sensibilities.
To be fair, proper ISO 8601 specifies hyphens as the separator between date elements, and I don’t think I’ve ever seen a XXXX-XX-XX (with hyphens) be used for YYYY-DD-MM. Just XX-XX could perhaps be ambiguous, but fortunately that’s not allowed by the standard, and anyone using just year-day for XXXX-XX is absolutely trolling. YYYY-DDD could have a use, though should really use a separate separator to not sort together IMO. A year-week designation could possibly look like XXXX-XX, but that seems unlikely to just be dropped in that format without context, at least to my western US sensibilities.