Parse dates by declared locale

The rules

These rules decide what a correct result is. Your answer is checked on this dataset and on hidden datasets that follow the same rules.

Input
  events(id, raw_date, locale) — text. id is unique. locale may be missing.

Rules
  Accept raw_date when it is:
    - an ISO date YYYY-MM-DD (any locale, including missing), or
    - a slash date D/M/YYYY or M/D/YYYY (1–2 digit day and month) AND locale is
        en-US → month first, or en-GB → day first.
  Quarantine with reason:
    invalid_date      raw_date is missing, or a slash date with a declared locale names a day that does not exist (31/02/2026)
    ambiguous_format  anything else, including a slash date whose locale is missing or not en-US/en-GB

Outputs (row order does not matter)
  clean(id text, date date)
  exceptions(id text, reason text)