{ "model": { "rank": 6787, "code": "thing-q235729", "model_id": "vr.tr.common-year", "name": "common year", "purpose": "Let an agent explain common years, relay Gregorian leap year rules, weekday patterns and calendar comparisons from calendar and astronomical sources, describe the named year types, and distinguish common years from leap years, fiscal years, the tropical year and lunar common years.", "family": "Thing Registry", "category": "Cross-cutting context", "status": "research-draft", "kind": "thing", "plane": "XCT", "domain": "XCT.TME", "industry": "", "version": "", "url": "/models/thing/q235729/", "tier": 2, "score": 58, "payload": { "layer": "wikidata", "aliases": [ "century common year", "common year starting and ending on Sunday", "common year starting and ending on Saturday", "common year starting and ending on Wednesday", "common year starting and ending on Friday", "common year starting and ending on Tuesday", "common year starting and ending on Monday", "common year starting and ending on Thursday" ], "aliasCount": 8, "merged": 8, "knownIn": 58, "facets": null, "markers": [], "lexicalClass": "", "senseRank": null, "alsoRegisteredAs": null, "source": { "dataset": "wikidata", "item": "Q235729", "url": "https://www.wikidata.org/wiki/Q235729", "license": "CC0 1.0" } }, "research": { "vercy": "1.0-draft", "publication": { "status": "research-draft", "adjudicationStatus": "unreviewed", "publishableCanonical": false, "generatedAt": "2026-09-13T20:39:27Z", "providers": [ "Claude" ], "breadth": "written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify", "pass": 2, "wave": 4, "engine": "claude" }, "metaModel": { "id": "THING-Q235729", "registryId": "vr.tr.common-year", "name": "common year", "version": "0.2.0-wave.4", "entryKind": "thing", "family": "Thing Registry", "domain": [ "XCT.TME" ], "status": "research-draft" }, "canonicalUrl": "https://ver.cy/models/thing/q235729/", "model": { "registry_id": "vr.tr.common-year", "name": "common year", "purpose": "Let an agent explain common years, relay Gregorian leap year rules, weekday patterns and calendar comparisons from calendar and astronomical sources, describe the named year types, and distinguish common years from leap years, fiscal years, the tropical year and lunar common years.", "definition": "A calendar year that is not a leap year, having 365 days in the Gregorian calendar, 52 weeks and one day, so that it starts and ends on the same day of the week, giving seven types of common year by starting weekday, such as a common year starting and ending on Sunday; century years not divisible by 400, such as 1900 and 2100, are century common years under the Gregorian rules, and in other calendars common years differ from embolismic or intercalary years.", "what_it_is_for": "Organising time in calendars.", "affordances": [ "explain the rules", "relay weekday patterns", "describe named year types", "distinguish related year concepts" ], "distinguishing_features": [ "365 days", "Same start and end weekday", "Seven types", "Century exceptions" ], "appearance": "Not a visible object; a calendar year.", "visual_identification": [ "Non-leap calendar year", "Century common year, common year starting and ending on Sunday, Saturday, Wednesday, Friday or Tuesday", "Leap years have 366 days; fiscal years follow accounting; the tropical year is astronomical; lunar calendars have different common years" ], "physical_properties": [ { "quantity": "days", "typical_range": "365", "unit": "count", "note": "Gregorian" }, { "quantity": "leap rule", "typical_range": "divisible by 4, except centuries not divisible by 400", "unit": "note", "note": "" }, { "quantity": "Gregorian reform", "typical_range": "1582", "unit": "year", "note": "" }, { "quantity": "common year types by weekday", "typical_range": "7", "unit": "count", "note": "" } ], "families_and_kinds": [ "seven weekday types of common year", "century common years", "common years in lunisolar calendars", "common years in the Julian calendar" ], "related_models": [ { "relation": "is a kind of", "target": "calendar year", "why": "in registry terms" }, { "relation": "is contrasted with", "target": "leap year", "why": "" }, { "relation": "includes", "target": "century common year", "why": "" }, { "relation": "is defined by", "target": "Gregorian calendar", "why": "" } ], "identifiers": [], "standards_and_regulation": [ "ISO 8601 calendar dates", "Gregorian calendar rules" ], "failure_modes_and_hazards": [ "Software bugs from wrong leap rules such as treating 1900 as leap", "Confusing calendar and fiscal years", "Assuming all calendars share rules" ], "in_scope": [], "out_of_scope": [], "characteristics": [] }, "sources": [], "structure": { "bundles": [ { "id": "understand", "name": "Understand", "description": "What a common year is.", "rationale": "Definition.", "layers": [ { "id": "definition", "name": "Definition", "description": "Definition.", "findings": [ { "id": "definition-finding", "name": "Definition", "description": "Definition.", "questions": [ { "text": "What is a common year, and how does it differ from leap years, fiscal years, the tropical year and lunar common years?", "kind": "definition" }, { "text": "Is the question about a specific year, software date rules or other calendars?", "kind": "boundary" } ] } ] }, { "id": "types", "name": "Types", "description": "Named types.", "findings": [ { "id": "types-finding", "name": "Types", "description": "Types.", "questions": [ { "text": "What are century common years and common years starting on each weekday?", "kind": "definition" }, { "text": "Which entry fits the specific year type?", "kind": "action" } ] } ] } ] }, { "id": "rules", "name": "Rules", "description": "Calendar rules.", "rationale": "Regulation.", "layers": [ { "id": "gregorian", "name": "Gregorian", "description": "Gregorian rules.", "findings": [ { "id": "gregorian-finding", "name": "Gregorian", "description": "Gregorian.", "questions": [ { "text": "How do the Gregorian leap year rules work, and why was 2000 a leap year but 1900 not?", "kind": "provenance" }, { "text": "Which references are standard?", "kind": "provenance" } ] } ] }, { "id": "weekdays", "name": "Weekdays", "description": "Weekday patterns.", "findings": [ { "id": "weekdays-finding", "name": "Weekdays", "description": "Weekdays.", "questions": [ { "text": "Why does a common year start and end on the same weekday, and how do dominical letters describe this?", "kind": "provenance" }, { "text": "Which sources are cited?", "kind": "provenance" } ] } ] } ] }, { "id": "computing", "name": "Computing", "description": "Computing.", "rationale": "Application.", "layers": [ { "id": "bugs", "name": "Bugs", "description": "Date bugs.", "findings": [ { "id": "bugs-finding", "name": "Bugs", "description": "Bugs.", "questions": [ { "text": "What leap year bugs have affected software?", "kind": "provenance" }, { "text": "Which entry fits leap year problem?", "kind": "action" } ] } ] }, { "id": "iso", "name": "ISO", "description": "ISO weeks.", "findings": [ { "id": "iso-finding", "name": "ISO", "description": "ISO.", "questions": [ { "text": "How do ISO week-numbering years relate to common years?", "kind": "provenance" }, { "text": "Which entry fits ISO week date?", "kind": "action" } ] } ] } ] }, { "id": "context", "name": "Context", "description": "Other calendars.", "rationale": "Context.", "layers": [ { "id": "lunisolar", "name": "Lunisolar", "description": "Lunisolar calendars.", "findings": [ { "id": "lunisolar-finding", "name": "Lunisolar", "description": "Lunisolar.", "questions": [ { "text": "How do Hebrew and Chinese calendars distinguish common and leap years?", "kind": "provenance" }, { "text": "Which entry fits Hebrew calendar?", "kind": "action" } ] } ] }, { "id": "julian", "name": "Julian", "description": "Julian calendar.", "findings": [ { "id": "julian-finding", "name": "Julian", "description": "Julian.", "questions": [ { "text": "How did the Julian calendar define common years?", "kind": "provenance" }, { "text": "Which entry fits Julian calendar?", "kind": "action" } ] } ] } ] } ] }, "openQuestions": [ "Should each weekday type be linked to year lists?", "How should calendar sources be linked?", "Should lunisolar common years be separate entries?" ], "statistics": { "bundles": 4, "layers": 8, "findings": 8, "questions": 16 } }, "draft": { "generator": "vr.draft.v3", "status": "draft-generated", "researched": false, "archetype": "abstract concept", "method": "Written from the archetype playbook - what this kind of thing needs beyond identity and provenance - and from the structure that recurred across 6,333 models already researched by two engines. Applied to this entry by rule. No source was read for this thing and no claim here is researched. This entry carries no facets of its own, so they were inferred from its domain - a guess about a whole domain applied to one thing.", "facetsInferred": true, "nextPass": "A researcher replaces this draft with a sourced specification. Treat every sentence below as a proposal to argue with.", "purpose": "Give an agent a durable, checkable way to recognise a common year, record what state it is in, and decide what may be done with it.", "whatItIs": "Let an agent explain common years, relay Gregorian leap year rules, weekday patterns and calendar comparisons from calendar and astronomical sources, describe the named year types, and distinguish common years from leap years, fiscal years, the tropical year and lunar common years.", "characteristics": { "substance": "abstract", "origin": "conceptual", "agency": "inert" }, "whatYouCanDoWithIt": [ "observed and measured" ], "distinguishingFeatures": [ "Names folded into this entry, which a task may need to split apart again: century common year, common year starting and ending on Sunday, common year starting and ending on Saturday, common year starting and ending on Wednesday, common year starting and ending on Friday, common year starting and ending on Tuesday, common year starting and ending on Monday, common year starting and ending on Thursday.", "8 finer distinctions are held as aliases rather than separate entries, because telling them apart needs a task that asks for it.", "Described in 58 Wikipedia languages, which is a measure of how widely the thing is known, not of how important it is." ], "openQuestionsForResearch": [ "Which of the bundles below does a real task actually need, and which are ceremony?", "What does this thing have that the facets do not capture at all?", "Which neighbouring kind is most often confused with a common year, and on what evidence are they told apart?" ], "whatItIsMadeOf": "an abstraction with no physical instance", "physicalCharacter": [ "Does nothing on its own; everything it does, something else did to it.", "These come from the domain this entry sits in rather than from the entry itself, so treat them as a first guess about the whole domain applied to one thing." ], "whatCanBeDoneWithIt": [ "observe it, measure it, record its state" ], "howItIsRecognised": [ "Nothing to see. What is recognised is an instance of it, and which instances count is exactly what is argued about." ], "relatedModels": [ { "relation": "covers", "note": "Finer kinds folded into this entry because telling them apart needs a task that asks for it. Each is a model waiting to be split out when one does.", "targets": [ "century common year", "common year starting and ending on Sunday", "common year starting and ending on Saturday", "common year starting and ending on Wednesday", "common year starting and ending on Friday", "common year starting and ending on Tuesday", "common year starting and ending on Monday", "common year starting and ending on Thursday" ] } ], "standing": "Described in 58 Wikipedia languages, which measures how widely it is written about rather than how important or how common it is. 8 finer distinctions are held inside this entry as names rather than as separate models.", "structure": { "bundles": [ { "id": "identity-and-classification", "name": "Identity, naming and classification", "description": "How an agent tells one common year from another, and a common year from things that resemble it.", "rationale": "Recognition comes before every other claim. Without stable identity nothing else in the model can be trusted to be about the same thing twice.", "layers": [ { "id": "naming-and-identifiers", "name": "Names and identifiers", "description": "The names this thing goes by and the identifiers that survive translation and time.", "findings": [ { "id": "preferred-name-and-aliases", "name": "Preferred name, aliases and local names", "description": "Which name to use, which names mean the same thing, and which merely sound similar.", "questions": [ { "id": "preferred-name-and-aliases-q01", "text": "What identifies and describes the name of a common year, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "preferred-name-and-aliases-q02", "text": "Who or what asserted this about the name of a common year, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "preferred-name-and-aliases-q03", "text": "What may an agent decide or do once the name of a common year is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] }, { "id": "stable-identifiers", "name": "Stable identifiers and external keys", "description": "Identifiers that keep pointing at this kind of thing across systems and languages.", "questions": [ { "id": "stable-identifiers-q01", "text": "What identifies and describes an identifier for a common year, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "stable-identifiers-q02", "text": "Who or what asserted this about an identifier for a common year, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "stable-identifiers-q03", "text": "What may an agent decide or do once an identifier for a common year is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "classification-and-granularity", "name": "Classification and granularity", "description": "Where a common year sits among kinds, and how finely a task needs to cut it.", "findings": [ { "id": "kind-and-parents", "name": "Kind, parents and neighbouring kinds", "description": "The classes this thing belongs to and the ones it is next to.", "questions": [ { "id": "kind-and-parents-q01", "text": "What identifies and describes the kind of a common year, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "kind-and-parents-q02", "text": "Who or what asserted this about the kind of a common year, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "kind-and-parents-q03", "text": "What may an agent decide or do once the kind of a common year is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] }, { "id": "distinguishing-features", "name": "Distinguishing features", "description": "What separates a common year from the things most often confused with it.", "questions": [ { "id": "distinguishing-features-q01", "text": "What identifies and describes what distinguishes a common year, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "distinguishing-features-q02", "text": "Who or what asserted this about what distinguishes a common year, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "distinguishing-features-q03", "text": "What may an agent decide or do once what distinguishes a common year is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] }, { "id": "state-and-lifecycle", "name": "State and lifecycle", "description": "The states a common year passes through and the events that move it between them.", "rationale": "Most decisions about a thing depend on what state it is in now, which is a claim with a time on it, not a property.", "layers": [ { "id": "lifecycle-stages", "name": "Lifecycle stages", "description": "From coming into existence to ceasing to be one of these.", "findings": [ { "id": "stages-and-transitions", "name": "Stages and transitions", "description": "The stages worth naming and what moves a common year between them.", "questions": [ { "id": "stages-and-transitions-q01", "text": "What identifies and describes the lifecycle of a common year, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "stages-and-transitions-q02", "text": "Who or what asserted this about the lifecycle of a common year, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "stages-and-transitions-q03", "text": "What may an agent decide or do once the lifecycle of a common year is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "observations-and-status", "name": "Observations and current status", "description": "What is observed about a common year, how often and by whom.", "findings": [ { "id": "observation-record", "name": "Observation record", "description": "How an observation of a common year is recorded so that it can be superseded rather than overwritten.", "questions": [ { "id": "observation-record-q01", "text": "What identifies and describes an observation of a common year, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "observation-record-q02", "text": "Who or what asserted this about an observation of a common year, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "observation-record-q03", "text": "What may an agent decide or do once an observation of a common year is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] }, { "id": "definitions-in-contest", "name": "Definitions and who holds them", "description": "What common year is taken to mean, and by whom.", "rationale": "When a field disagrees about a concept, the disagreement is the content. A model that picks one definition silently destroys the information.", "layers": [ { "id": "competing-definitions", "name": "Competing definitions", "description": "The main readings and the traditions behind them.", "findings": [ { "id": "definition-map", "name": "Definitions and their holders", "description": "Each definition with the school or body that holds it.", "questions": [ { "id": "definition-map-q01", "text": "Which definitions of common year are in use, and which tradition or body holds each?", "kind": "definition" }, { "id": "definition-map-q02", "text": "What turns on the difference between them in practice?", "kind": "boundary" } ] } ] }, { "id": "operationalisation", "name": "Operationalisation", "description": "How it is measured or applied when it has to be.", "findings": [ { "id": "operational-record", "name": "Measures and proxies", "description": "Instruments and indicators used to stand in for it.", "questions": [ { "id": "operational-record-q01", "text": "How is common year operationalised or measured in practice, and by what instrument?", "kind": "measurement" }, { "id": "operational-record-q02", "text": "What does that operationalisation leave out, and when does that matter?", "kind": "boundary" } ] } ] } ] }, { "id": "instances-and-use", "name": "Instances, use and consequence", "description": "What counts as an instance of common year and what follows from calling something that.", "rationale": "Applying a concept is an act with consequences, so a model must say what the label licenses and what it does not.", "layers": [ { "id": "instances", "name": "What counts as an instance", "description": "Clear cases, borderline cases and non-cases.", "findings": [ { "id": "instance-tests", "name": "Tests for an instance", "description": "What would settle whether something falls under it.", "questions": [ { "id": "instance-tests-q01", "text": "What would settle whether something is an instance of common year?", "kind": "boundary" }, { "id": "instance-tests-q02", "text": "Which borderline cases are argued about, and on what grounds?", "kind": "definition" } ] } ] }, { "id": "consequence", "name": "Consequence of application", "description": "Rights, duties or decisions that follow from the label.", "findings": [ { "id": "consequence-record", "name": "What the label licenses", "description": "What an agent may do once something is classified this way.", "questions": [ { "id": "consequence-record-q01", "text": "What follows practically once something is treated as common year?", "kind": "action" }, { "id": "consequence-record-q02", "text": "What must an agent not infer from the label alone?", "kind": "action" } ] } ] } ] }, { "id": "provenance-and-evidence", "name": "Provenance, evidence and time", "description": "Where every claim about a common year came from and when it held.", "rationale": "A claim without a source and a time cannot be superseded, only overwritten, and an agent that overwrites loses the ability to explain itself.", "layers": [ { "id": "source-and-authority", "name": "Source and authority", "description": "Who said it, on what evidence, and how strongly.", "findings": [ { "id": "claim-provenance", "name": "Claim provenance and confidence", "description": "The authority behind each claim about a common year and how confident it is.", "questions": [ { "id": "claim-provenance-q01", "text": "What identifies and describes a claim about a common year, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "claim-provenance-q02", "text": "Who or what asserted this about a claim about a common year, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "claim-provenance-q03", "text": "What may an agent decide or do once a claim about a common year is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "time-and-versions", "name": "Time, versions and supersession", "description": "When a claim was true, when it was learnt, and what replaced it.", "findings": [ { "id": "validity-and-supersession", "name": "Validity period and supersession", "description": "How an old claim about a common year is retired without being erased.", "questions": [ { "id": "validity-and-supersession-q01", "text": "What identifies and describes the validity of a claim about a common year, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "validity-and-supersession-q02", "text": "Who or what asserted this about the validity of a claim about a common year, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "validity-and-supersession-q03", "text": "What may an agent decide or do once the validity of a claim about a common year is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] } ] }, "statistics": { "bundles": 5, "layers": 10, "findings": 12, "questions": 32 } } } }