{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.april-19","code":"thing-q2523","url":"https://ver.cy/models/thing/q2523/","name":"April 19","alternateNames":[],"kind":"thing","status":"published","version":"0.2.0-wave.2","language":"en","classifiers":{"family":"Thing Registry","category":"Cross-cutting context","entryKind":"thing","plane":"XCT","domain":["XCT.TME"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"April 19, day 109 (day 110 in leap years) of the year in the Gregorian calendar, with 256 days remaining in both common and leap years. Observances on this date vary by country and tradition.","purpose":"Let an agent handle April 19 as a calendar date with weekday computation, observances attributed to their traditions and sourced events.","scope":{"in":[],"out":[],"boundaries":[]},"distinguishingFeatures":["The nineteenth day of April","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 April 19 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 April 19 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 April 19, 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 April 19?","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":["Compute the weekday of April 19 and its day number, 109 or 110.","Explain observances on April 19 and how some movable feasts may fall on it."],"mustNot":["Present a movable feast as fixed on April 19 every year.","List April 19 anniversaries without sources, especially anniversaries of violence.","Use April 19 anniversaries to celebrate or promote extremist acts.","Ignore the calendar in use when dating older events to April 19."],"requiresHuman":["Publishing remembrance content on the anniversary of an attack or disaster."]},"ethics":{"considerations":["Some April anniversaries mark mass killings; families of victims deserve care in how they are told.","Dates are a shared civic tool and must be reliable."],"affectedParties":["Families of victims","Communities with observances","Readers relying on the date"]},"owners":{"steward":"Nobody: the Gregorian calendar is held in common.","roles":[],"masterSystems":[]},"relations":[{"target":"Q11186284","type":"parent","note":"registry parent class"},{"target":"April","type":"related","note":"month"},{"target":"April 18","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.april-19","Wikidata: Q2523 (https://www.wikidata.org/wiki/Q2523)","ISO 8601: --04-19 recurring date"]},"properties":{"applicability":"not-applicable","items":["day of year: 109 or 110 day - common year, leap year where different","days remaining: 256 days"]},"recognition":{"applicability":"optional","items":["Written 19 April or April 19","ISO format --04-19","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 Q2523: April 19","url":"https://www.wikidata.org/wiki/Q2523","note":"identity and sense of the item"},{"title":"Wikipedia: April 19","url":"https://en.wikipedia.org/wiki/April_19","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-q2523/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q2523/spec.json"],"providers":["Claude"],"researchStatus":"unreviewed","generatedAt":"2026-09-11T22:57:42Z","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}}