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Published

March 20

vr.tr.march-20 · thing-q2427

Let an agent handle March 20 as a calendar date with weekday computation, observances attributed to their traditions and sourced events.

Thing Registry Cross-cutting context XCT.TME
Bundle → Layer → Finding → QuestionsClassifiersWhat it isWhy it existsDistinguishing featuresWhat robots and AI may and may not doMoral aspectsOwnersLinks to other meta-modelsIdentity and identifiersDirect propertiesRecognitionCapabilities and actionsHazards and failure modesStandards and interfacesContext of useSources

Bundle → Layer → Finding → Questions Filled

4 bundles · 8 layers · 8 findings · 16 questions

Date Calendar facts.

Weekday

Computation.

Weekday

Weekday.

  1. On which weekday does March 20 fall in this year? measurement
  2. Is it a leap year? boundary

Calendar

Julian or Gregorian.

Calendar

Calendar system.

  1. Is the Julian or Gregorian calendar meant? boundary
  2. What is the equivalent date in the other calendar? measurement
Observances Holidays.

Holiday

Public holiday.

Holiday

Holiday status.

  1. Is March 20 a public holiday or observance here? provenance
  2. Which tradition or law sets it? provenance

Attribution

Traditions.

Attribution

Attributed observances.

  1. Which countries or communities observe something on this date, according to them? provenance
  2. Is the observance attributed rather than assumed? boundary
History Past events.

Events

On this day.

Events

Historical events.

  1. Which notable events happened on March 20, according to reliable sources? provenance
  2. Are dates given in the same calendar? boundary

Anniversaries

Recurring.

Anniversaries

Anniversaries.

  1. Which anniversaries fall on this date this year? provenance
  2. Which are round numbers? measurement
Planning Scheduling.

Countdown

Days until.

Countdown

Countdown.

  1. How many days until the next March 20? measurement
  2. From which date? definition

Work

Working day.

Work

Working day.

  1. Is it a working day for this organisation? provenance
  2. Do deadlines move? boundary

Classifiers Filled

Family
Thing Registry
Category
Cross-cutting context
Entry kind
thing
Plane
XCT
Domain
XCT.TME

What it is Filled

March 20, day 79 (day 80 in leap years) of the year in the Gregorian calendar, with 286 days remaining in both common and leap years. Observances on this date vary by country and tradition; the March equinox often falls on this date, and it is the International Day of Happiness.

Why it exists Filled

Let an agent handle March 20 as a calendar date with weekday computation, observances attributed to their traditions and sourced events.

Distinguishing features Filled

  • The twentieth day of March
  • Weekday varies by year
  • Observances vary by place
  • Julian and Gregorian dates differ by 13 days in this era

What robots and AI may and may not do Filled

Must not

  • Claim the equinox always falls on March 20 or at the same hour everywhere.
  • Present Nowruz or other new year celebrations near the equinox as fixed to March 20 everywhere.
  • Report on-this-day events without sources.

Only with a human decision

  • Scheduling time-critical or ritual events tied to the exact equinox moment.

May

  • Compute the day of the year and weekday for March 20 in a given year.
  • State the exact time of the March equinox for a year from an astronomical source and note it may fall on another date.
  • List observances such as the International Day of Happiness with their origin.

Moral aspects Filled

  • The equinox marks new year and religious calendars for many communities, which deserve accuracy.
  • Dates near hemispheric seasons are often described only from a northern viewpoint.

Who is affected

  • Communities observing the equinox
  • People in the southern hemisphere

Owners Filled

Steward

Nobody owns a date; calendar standards and astronomical almanacs define it.

Links to other meta-models Filled

parent

  • Q11187215 - registry parent class

related

  • March - month
  • March 19 - date
  • calendar date - category
  • ISO 8601 - notation

What else AI and robots need to interact with it Filled

Identity and identifiers required Filled

  • Vercy registry: vr.tr.march-20
  • Wikidata: Q2427 (https://www.wikidata.org/wiki/Q2427)
  • ISO 8601: --03-20 recurring date

Direct properties not applicable Not applicable

  • day of year: 79 or 80 day - common year, leap year where different
  • days remaining: 286 days

Plane XCT: no invented physical properties.

Recognition optional Filled

  • Written 20 March or March 20
  • ISO format --03-20
  • Observances vary by country and tradition
  • A date on calendars.

Capabilities and actions required Filled

  • compute its weekday in a given year
  • check local and international observances
  • find sourced historical events
  • schedule events

Hazards and failure modes required Filled

  • Assuming observances are universal
  • Unsourced on-this-day events
  • Mixing Julian and Gregorian dates

Standards and interfaces required Filled

  • ISO 8601
  • National public holiday laws

Context of use required Filled

  • A calendar date for scheduling, holidays and anniversaries.
  • the recurring calendar date
  • specific dated days in given years

Sources Filled

  1. Wikidata item Q2427: March 20 - identity and sense of the item
  2. Wikipedia: March 20 - general description of the item

Open questions

  • Should dated days be separate entries?
  • How should observances be linked?
  • How should events be sourced?

Machine files

Card as JSON Specification Card backlog vercy.card/1

Provenance

thing registry research (pass 2) · unreviewed

Built from: models/things/publications/thing-q2427/spec.json