Check Date rule

meta {
    title: "Check Date";
    version: "1.1_2023-05-20";
    author: "CjMalone";
    link: "https://josm.openstreetmap.de/wiki/Rules/CheckDate";
    baselanguage: "en";
}

*[check_date][check_date!~/^\d{4}(-[01]\d(-\d\d([T ]\d\d:\d\d:\d\dZ?)?)?)?$/] {
    throwWarning: "check_date should be a valid ISO 8601 date (YYYY-MM-DD)";
}

Rules_CheckDate.validator.mapcss, Rules_CheckDate.zip