{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.may-21","code":"thing-q2580","url":"https://ver.cy/models/thing/q2580/","name":"May 21","alternateNames":[],"kind":"thing","status":"published","version":"0.2.0-wave.3","language":"en","classifiers":{"family":"Thing Registry","category":"Cross-cutting context","entryKind":"thing","plane":"XCT","domain":["XCT.TME"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"May 21, day 141 (day 142 in leap years) of the year in the Gregorian calendar, with 224 days remaining in both common and leap years. May 21 is the World Day for Cultural Diversity for Dialogue and Development and is a national or memorial day in several countries.","purpose":"Let an agent handle May 21 as a calendar date with weekday computation, observances attributed to their traditions and sourced events.","scope":{"in":[],"out":[],"boundaries":[]},"distinguishingFeatures":["The twenty-first day of May","Weekday varies by year","Observances vary by place","Julian and Gregorian dates differ by 13 days in this era"],"structure":{"bundles":[{"id":"date","name":"Date","description":"Calendar facts.","layers":[{"id":"weekday","name":"Weekday","description":"Computation.","findings":[{"id":"weekday-finding","name":"Weekday","description":"Weekday.","questions":[{"text":"On which weekday does May 21 fall in this year?","kind":"measurement"},{"text":"Is it a leap year?","kind":"boundary"}]}]},{"id":"calendar","name":"Calendar","description":"Julian or Gregorian.","findings":[{"id":"calendar-finding","name":"Calendar","description":"Calendar system.","questions":[{"text":"Is the Julian or Gregorian calendar meant?","kind":"boundary"},{"text":"What is the equivalent date in the other calendar?","kind":"measurement"}]}]}]},{"id":"observances","name":"Observances","description":"Holidays.","layers":[{"id":"holiday","name":"Holiday","description":"Public holiday.","findings":[{"id":"holiday-finding","name":"Holiday","description":"Holiday status.","questions":[{"text":"Is May 21 a public holiday or observance here?","kind":"provenance"},{"text":"Which tradition or law sets it?","kind":"provenance"}]}]},{"id":"attribution","name":"Attribution","description":"Traditions.","findings":[{"id":"attribution-finding","name":"Attribution","description":"Attributed observances.","questions":[{"text":"Which countries or communities observe something on this date, according to them?","kind":"provenance"},{"text":"Is the observance attributed rather than assumed?","kind":"boundary"}]}]}]},{"id":"history","name":"History","description":"Past events.","layers":[{"id":"events","name":"Events","description":"On this day.","findings":[{"id":"events-finding","name":"Events","description":"Historical events.","questions":[{"text":"Which notable events happened on May 21, according to reliable sources?","kind":"provenance"},{"text":"Are dates given in the same calendar?","kind":"boundary"}]}]},{"id":"anniversaries","name":"Anniversaries","description":"Recurring.","findings":[{"id":"anniversaries-finding","name":"Anniversaries","description":"Anniversaries.","questions":[{"text":"Which anniversaries fall on this date this year?","kind":"provenance"},{"text":"Which are round numbers?","kind":"measurement"}]}]}]},{"id":"planning","name":"Planning","description":"Scheduling.","layers":[{"id":"countdown","name":"Countdown","description":"Days until.","findings":[{"id":"countdown-finding","name":"Countdown","description":"Countdown.","questions":[{"text":"How many days until the next May 21?","kind":"measurement"},{"text":"From which date?","kind":"definition"}]}]},{"id":"work","name":"Work","description":"Working day.","findings":[{"id":"work-finding","name":"Work","description":"Working day.","questions":[{"text":"Is it a working day for this organisation?","kind":"provenance"},{"text":"Do deadlines move?","kind":"boundary"}]}]}]}]},"agentConduct":{"may":["State the date's position in the calendar and days remaining.","List observances on this date, naming who declared each one."],"mustNot":["Present a day about cultural diversity as a mandate for any particular policy.","Invent anniversaries or memorial days for the date.","Treat a national memorial day in one country as observed everywhere.","Attribute a campaign to an international body that did not endorse it."],"requiresHuman":["Publishing a commemorative or campaign statement tied to this date."]},"ethics":{"considerations":["Days about diversity are used to decorate organizations that do little.","Memorial days matter deeply to the communities who keep them."],"affectedParties":["Communities marking the day","Audiences of campaigns","Workers affected by holiday rules"]},"owners":{"steward":"Nobody: a calendar date held in common; declaring bodies define their observances.","roles":[],"masterSystems":[]},"relations":[{"target":"Q11187254","type":"parent","note":"registry parent class"},{"target":"May","type":"related","note":"month"},{"target":"May 20","type":"related","note":"date"},{"target":"calendar date","type":"related","note":"category"},{"target":"ISO 8601","type":"related","note":"notation"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.may-21","Wikidata: Q2580 (https://www.wikidata.org/wiki/Q2580)","ISO 8601: --05-21 recurring date"]},"properties":{"applicability":"not-applicable","items":["day of year: 141 or 142 day - common year, leap year where different","days remaining: 224 days"]},"recognition":{"applicability":"optional","items":["Written 21 May or May 21","ISO format --05-21","Observances vary by country and tradition","A date on calendars."]},"capabilities":{"applicability":"required","items":["compute its weekday in a given year","check local and international observances","find sourced historical events","schedule events"]},"hazards":{"applicability":"required","items":["Assuming observances are universal","Unsourced on-this-day events","Mixing Julian and Gregorian dates"]},"interfaces":{"applicability":"required","items":["ISO 8601","National public holiday laws"]},"context":{"applicability":"required","items":["A calendar date for scheduling, holidays and anniversaries.","the recurring calendar date","specific dated days in given years"]}},"sources":[{"title":"Wikidata item Q2580: May 21","url":"https://www.wikidata.org/wiki/Q2580","note":"identity and sense of the item"},{"title":"Wikipedia: May 21","url":"https://en.wikipedia.org/wiki/May_21","note":"general description of the item"}],"openQuestions":["Should dated days be separate entries?","How should observances be linked?","How should events be sourced?"],"resources":{"spec":"/models/things/publications/thing-q2580/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q2580/spec.json"],"providers":["Claude"],"researchStatus":"unreviewed","generatedAt":"2026-09-13T00:32:31Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"not-applicable","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-06T19:51:57+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass","interaction.properties":"Plane XCT: no invented physical properties."},"score":1.0}}