Time / Calendar

A time scale is a governed system for locating instants, characterised by its defining authority, epoch, unit, and whether it is continuous (TAI, GPS) or subject to discontinuities (UTC). Statements are only comparable when the scale is declared; the current relation UTC = TAI - 37 s has been in force since 2017-01-01 and is itself a dated fact.

Questions

1. Which named time scale does this temporal value use, and is that scale explicitly declared or merely assumed?definition
   Expected answer

   • scale identifier
   • scale declaration mode (explicit, inherited, assumed)
   • default scale for the containing model
2. Which body defines and publishes this scale, and through which serial publication is its realisation disseminated?authority
   Expected answer

   • defining authority
   • publishing authority
   • publication series identifier
   • latest issue identifier and date
3. Is the scale continuous, or may it contain inserted or removed seconds that break naive arithmetic?classification
   Expected answer

   • continuity class (continuous, stepped, smeared, undefined)
   • discontinuity mechanism
   • known discontinuity count
4. What is the offset from this scale to UTC at a given instant, and from when is that offset valid?measurement
   Expected answer

   • offset value with unit
   • valid-from instant
   • valid-until instant or open
   • source publication reference
5. Which scale is used for the underlying storage representation, and does it differ from the scale used for display or comparison?interoperability
   Expected answer

   • storage scale identifier
   • comparison scale identifier
   • conversion rule reference

Artifacts

• Time scale registerThe curated set of time scales recognised by the adopting Dimension, with epochs, continuity classes and inter-scale offset histories.
• Scale realisation bulletinA dated, numbered publication relating the scale to its local realisations, such as BIPM Circular T.

Leap seconds are announced by IERS in serial Bulletin C notices, tabulated in a machine-readable list carrying an explicit expiration, represented in timestamps as second value 60, and are subject to a standing CGPM decision to increase the permitted UT1-UTC difference in or before 2035. A leap table is therefore a perishable artifact, not a constant.

Questions

1. Which body decides a leap adjustment, and by which dated instrument was the most recent decision announced?authority
   Expected answer

   • deciding body
   • bulletin series and number
   • issue date
   • decision outcome (insert, remove, none)
2. What is the cumulative TAI-UTC value at a given instant, and when does the consulted leap table expire?temporal
   Expected answer

   • cumulative offset in seconds
   • effective-from instant
   • table last-update instant
   • table expiration instant
3. How does this system represent or avoid the 60th second, and is that behaviour declared?constraint
   Expected answer

   • leap representation policy (represent as :60, smear, reject, clamp)
   • smear window and shape if applicable
   • affected interfaces
4. What happens to stored durations and orderings computed before a leap adjustment took effect?lifecycle
   Expected answer

   • recomputation policy
   • affected record classes
   • recomputation event log reference
5. How will the planned change to the UT1-UTC tolerance by 2035 affect assumptions currently baked into this Dimension?decision
   Expected answer

   • dependency inventory on leap-second insertion
   • planned migration action
   • owner
   • target date
6. Is the leap table currently in use still valid, and what is done when it has expired?validation
   Expected answer

   • freshness check result
   • expiry instant
   • stale-data fallback behaviour
   • alerting target

Artifacts

• Leap second tableMachine-readable table of leap events with cumulative offsets, a last-update marker and an explicit expiration marker.
• Leap decision noticeThe numbered bulletin announcing insertion or non-insertion of a leap second at the next opportunity.

An instant is recorded using an RFC 3339 date-time with an explicit numeric offset or Z, optionally annotated per RFC 9557 with the originating time zone and calendar. The distinct meanings of Z, +00:00 and -00:00, the declared fractional precision, and the separation of event time from observation or ingestion time are all part of the record's meaning.

Questions

1. Does every recorded instant carry an explicit offset or Z, and are unqualified local times rejected at the boundary?validation
   Expected answer

   • offset presence rule
   • validation error code for missing offset
   • count of legacy values lacking offset
2. Is the offset a known local offset, an assertion of UTC preference, or a declaration that the local offset is unknown?definition
   Expected answer

   • offset form used (Z, +00:00, -00:00, numeric)
   • interpretation note
   • originating locality if known
3. What fractional-second precision is stored, and is stored precision distinguished from measured precision?measurement
   Expected answer

   • stored decimal places
   • measurement resolution
   • truncation or rounding rule
4. Are event time and observation or ingestion time recorded separately for this record class?provenance
   Expected answer

   • event time field
   • observation time field
   • ingestion time field
   • clock source for each
5. When an instant is annotated with a time zone, is that annotation critical, and what must happen if it contradicts the offset?exception
   Expected answer

   • annotation criticality flag
   • conflict detection rule
   • action on conflict (reject, prefer offset, prefer zone)

Artifacts

• Timestamp conformance profileA declared profile stating which granularities, offset forms, annotations and precision this Dimension accepts and emits, as required when adopting an ISO 8601 profile.

A civil zone is identified by a tz identifier in Area/Location form, which may be a primary zone or a backward-compatibility link to another zone. CLDR maintains a deliberately more stable identifier layer with documented alias equivalences, because zone names, boundaries, offsets and abbreviations are explicitly not all stable interfaces.

Questions

1. Which identifier scheme is this zone identifier drawn from, and is the value canonical or an alias?identity
   Expected answer

   • identifier scheme
   • identifier value
   • canonical form
   • alias-of target
2. Which stable identifier does this Dimension persist when the upstream registry renames or relinks a zone?interoperability
   Expected answer

   • persisted identifier layer (tz canonical, CLDR BCP47 key, internal surrogate)
   • mapping table reference
   • rename handling rule
3. Are zone abbreviations, numeric offsets or country codes ever used to identify a zone in this system?constraint
   Expected answer

   • prohibited identifier forms in use
   • remediation plan
   • affected interfaces
4. What happens to stored references when a zone is split, merged or retired upstream?lifecycle
   Expected answer

   • split or merge event record
   • superseding identifier
   • migration rule for stored references
   • effective instant
5. Which geographic region does this identifier actually cover, and is that coverage authoritative for jurisdictional purposes?spatial
   Expected answer

   • region description from the zone table
   • representative coordinates
   • jurisdiction reference
   • authoritativeness caveat

Artifacts

• Zone identifier crosswalkMapping between tz canonical identifiers, backward links, CLDR stable keys, legacy platform identifiers and any internal surrogates.

A zone's behaviour is a sorted series of transitions, each selecting a local time type consisting of a UTC offset, a daylight indicator and a designation. Rules need not alternate between two states, may change more than twice per year, and future behaviour beyond the last explicit transition is governed by a projected rule string or by a stated validity limit.

Questions

1. What is the complete ordered series of offset transitions for this zone over the period the data must serve?composition
   Expected answer

   • transition instants on the reference scale
   • offset before
   • offset after
   • daylight indicator
   • designation
2. Until what instant is the zone data explicitly valid, and how is behaviour beyond that point derived?temporal
   Expected answer

   • validity upper bound
   • projection rule expression
   • truncation start point
   • projection reliability note
3. Was a given transition a historical fact, a scheduled future change, or a prediction from a repeating rule?state
   Expected answer

   • transition status (historical, scheduled, predicted)
   • announcing instrument reference
   • confidence
4. Which upstream release supplied this transition series, and has any transition changed between releases?provenance
   Expected answer

   • upstream release identifier
   • previous value
   • change instant
   • change reason
5. Is the recorded pre-1970 history evidence-backed or reconstructed, and is that distinction visible to consumers?evidence
   Expected answer

   • evidence class
   • source citation
   • known-inaccuracy flag
   • consumer-facing warning
6. Which projection formats must this transition series be emitted in, and are they lossless with respect to each other?interoperability
   Expected answer

   • target formats
   • fields lost per format
   • round-trip test result

Artifacts

• Zone information fileBinary projection of the transition series, local time types, designations, leap records and projection footer.
• Zone observance componentTextual calendaring projection of a zone as standard and daylight observances with offsets, names and recurrence or explicit dates.

Around a transition, a local wall-clock time may be skipped or may occur twice, and a supplied offset may disagree with the supplied zone. A conforming system must declare a deterministic resolution policy; where a zone annotation is marked critical the inconsistency must be acted upon rather than silently ignored.

Questions

1. When a stated local time falls in a transition gap, is it rejected, shifted forward, or shifted by the gap duration?exception
   Expected answer

   • gap policy code
   • shift amount rule
   • error surface
   • affected operations
2. When a stated local time is ambiguous, is the earlier or later occurrence chosen, and can the caller override?decision
   Expected answer

   • default disambiguation choice
   • caller override parameter
   • recorded chosen offset
3. If the supplied offset contradicts the supplied zone identifier, which wins, and is the annotation critical?constraint
   Expected answer

   • criticality flag
   • precedence rule
   • rejection condition
   • diagnostic emitted
4. Is the resolved offset persisted alongside the local time so the resolution is reproducible later?validation
   Expected answer

   • persisted resolved offset
   • resolution timestamp
   • zone data release used
5. How are recurring local-time series handled when a future instance lands in a gap created by a later rule change?process
   Expected answer

   • re-expansion trigger
   • instance adjustment rule
   • notification to dependents

Artifacts

• Disambiguation policy statementPublished statement of gap, overlap and conflict handling, so that consumers can reproduce a resolution.

Standard time and daylight saving arrangements are set by legal instruments — directives, statutes, regulations and proclamations — with a defined administering authority and change procedure. The tz database mirrors the resulting consensus on the ground and its coordinator explicitly does not set policy, so the legal instrument, not the database entry, is the authority of record.

Questions

1. Which authority is legally competent to change standard time or daylight arrangements for this territory?authority
   Expected answer

   • competent authority
   • statutory basis citation
   • scope of competence
2. By which dated instrument was the current arrangement established, and where was it officially published?provenance
   Expected answer

   • instrument title
   • instrument identifier
   • official publication reference
   • publication date
3. What is the procedure and evidentiary threshold for changing a boundary or an exemption?process
   Expected answer

   • petition or proposal route
   • evidence requirement
   • consultation step
   • decision instrument
4. When does the change take legal effect, and how much notice was given before that instant?temporal
   Expected answer

   • effective instant
   • announcement instant
   • notice period
   • retroactivity flag
5. Who owns the record of this arrangement in the adopting Dimension, and who mirrors it into machine data?ownership
   Expected answer

   • record owner
   • mirroring steward
   • upstream mirror release in which it appeared
6. Is the machine data currently consistent with the legal instrument, and what is done while they diverge?quality
   Expected answer

   • divergence flag
   • divergence description
   • interim override rule
   • review date

Artifacts

• Legal instrument citation recordStructured citation of the statute, directive, regulation or proclamation governing civil time for a territory, with official publication reference.
• Zone change noticeOperational notice issued when a jurisdiction's zone or daylight rule changes, carrying announcement instant, effective instant and affected zone identifiers.

A calendar system is identified by a registered key from the Unicode calendar registry, which recurrence and timestamp standards reference normatively. The registry distinguishes systems that differ only in determination method — tabular civil, tabular astronomical, Umm al-Qura and sighting-based Hijri variants — and marks deprecated keys with preferred replacements; leap months are denoted by an L suffix in recurrence contexts.

Questions

1. Which registered calendar key identifies this system, and is that key current or deprecated in favour of another?identity
   Expected answer

   • calendar key
   • registry version
   • deprecation status
   • preferred replacement key
2. Is the system solar, lunar or lunisolar, and does it use intercalary days, intercalary months or both?classification
   Expected answer

   • astronomical class
   • intercalation mechanism
   • cycle length if tabular
3. Where two keys describe the same tradition but differ in determination method, which one governs this record?decision
   Expected answer

   • selected key
   • determination method (tabular, computed, observational)
   • selection rationale
   • authority for the method
4. How are leap months represented and ordered when a date or recurrence falls in one?composition
   Expected answer

   • leap month notation
   • position relative to the base month
   • behaviour when the leap month is absent in a target year
5. Which calendar is assumed when none is declared, and is that assumption territory-dependent?constraint
   Expected answer

   • default calendar key
   • territory-based override source
   • declaration requirement
6. Can this calendar's dates be converted losslessly to and from the proleptic Gregorian representation used for storage?interoperability
   Expected answer

   • conversion library and version
   • round-trip test result
   • known lossy ranges

Artifacts

• Calendar registry entryThe adopted subset of the calendar registry, recording key, description, since-version and deprecation state for each calendar supported by the Dimension.

An era is a named span within a calendar system with a mnemonic code, a numeric type for name lookup, and start and end dates expressed as proleptic Gregorian dates; eras are ordered by start date and may be inherited between related calendars. Eras are mutable reference data: a new era can be proclaimed and existing systems must absorb it.

Questions

1. Which era does a given date fall in, and how is the era boundary expressed unambiguously?temporal
   Expected answer

   • era code
   • start date in proleptic Gregorian
   • end date or open
   • boundary inclusivity
2. What identifies the era stably — the mnemonic code or the numeric type used for name lookup?identity
   Expected answer

   • era code
   • numeric type
   • alias codes
   • stability note
3. Does this calendar inherit eras from another calendar, and does that inheritance affect ordering?relationship
   Expected answer

   • inherited-from calendar key
   • inheritance scope
   • resulting ordered era list
4. What process adds a new era, and what is the lead time between proclamation and effect?lifecycle
   Expected answer

   • proclaiming authority
   • proclamation instant
   • effective instant
   • data release in which the era appeared
5. Are year numbers within the era counted forward only, and how are dates before the calendar's epoch expressed?constraint
   Expected answer

   • year numbering direction
   • proleptic extension policy
   • representation for pre-epoch dates

Artifacts

• Era tableOrdered table of eras per calendar system with codes, numeric types, boundaries and inheritance.

First day of week, minimum days in the first week and weekend start and end are territory-scoped supplemental data, and can be overridden by an explicit region key. Week numbering under the ISO rules is itself a distinct registered calendar key, and recurrence rules carry their own week-start parameter that must not be silently inherited from locale.

Questions

1. Which territory's week data governs this computation, and how was that territory determined?spatial
   Expected answer

   • territory code
   • determination path (explicit, region override, inferred)
   • fallback territory
2. What are the first day of week, the minimum days in the first week and the weekend days for that territory?definition
   Expected answer

   • first day
   • minimum days
   • weekend start day
   • weekend end day
   • partial-day weekend note
3. Does week numbering follow the ISO week-date rules or the territory's own rules, and is that choice declared?classification
   Expected answer

   • week numbering system
   • calendar key used
   • declaration location
4. Is the week-start used in recurrence expansion the same as the locale week-start, and what happens if they differ?constraint
   Expected answer

   • recurrence week-start parameter
   • locale week-start
   • divergence handling
   • example divergent result
5. How is a weekend that is not Saturday and Sunday represented in working-day calculations?interoperability
   Expected answer

   • weekend day set
   • non-contiguous weekend support
   • downstream consumers affected

Artifacts

• Week data profileAdopted territory-by-territory week and weekend data with declared overrides, used as the base of all working-day computation.

Temporal entities divide into instants of zero extent and intervals with extent, with proper intervals having distinct beginning and end. Periods are expressed either as start and end or as start and duration, and durations split into exact machine quantities and nominal calendar-clock descriptions whose length depends on where they are applied — a distinction that matters at transitions and at month boundaries.

Questions

1. Is this value an instant or an interval, and if an interval, are its endpoints distinct?definition
   Expected answer

   • shape class
   • beginning value
   • end value
   • proper interval flag
2. Is the interval expressed as start and end or as start and duration, and are the endpoints inclusive or exclusive?composition
   Expected answer

   • period form
   • inclusivity of start
   • inclusivity of end
   • normalisation rule
3. Is the duration an exact quantity or a nominal calendar description, and which units may it carry?measurement
   Expected answer

   • duration kind
   • unit set
   • sign convention
   • normalisation policy
4. How is a nominal duration added across a zone transition or a short or long month?constraint
   Expected answer

   • addition algorithm
   • overflow clamping rule
   • transition handling rule
   • worked example
5. Can an interval be unbounded at either end, and how is that represented distinctly from a missing value?exception
   Expected answer

   • unbounded start representation
   • unbounded end representation
   • null versus unbounded distinction

A temporal statement carries a granularity that must be declared rather than inferred from the digits present, ranging from year through fractional second. Date-only values and all-day semantics are distinct from midnight-precision date-times, and an adopting profile must state which granularities and offset forms it supports.

Questions

1. What granularity does this value actually assert, and is that recorded separately from its serialised form?quality
   Expected answer

   • asserted granularity
   • serialised digit count
   • granularity field location
2. Is this a date-only or all-day value, and is it therefore zone-independent?classification
   Expected answer

   • all-day flag
   • zone independence flag
   • display rule
3. Which granularities and offset forms does this Dimension's adopted profile accept on input and emit on output?requirement
   Expected answer

   • accepted granularity set
   • emitted granularity set
   • offset forms accepted
   • rejection behaviour
4. How is a value that is known only approximately, or only to a bounded range, represented without inventing precision?evidence
   Expected answer

   • representation chosen (bounded interval, granularity downgrade, qualifier)
   • evidence basis
   • confidence statement
5. Is comparison between values of different granularity defined, and what does it return when they overlap?validation
   Expected answer

   • comparison semantics
   • indeterminate result handling
   • test cases

Artifacts

• Temporal precision profileThe Dimension's declaration of accepted and emitted granularities, all-day semantics, and representation of bounded or open values.

Three bindings exist and must be distinguished per field: a floating local value that occurs at the same wall-clock reading everywhere, a local value bound to a named zone, and an absolute instant with an explicit offset or Z. The binding determines which companion fields are mandatory and which operations are valid, and it is a semantic property of the field, not of its serialisation.

Questions

1. Which binding does this field use, and where is that binding declared for machine consumption?requirement
   Expected answer

   • binding code
   • declaration location
   • default binding for the model
2. Which companion fields are mandatory for this binding — zone identifier, calendar key, granularity, resolved offset?constraint
   Expected answer

   • required companion field list
   • validation rule
   • error code on omission
3. Is a floating value ever silently converted to an absolute instant on storage or transport?validation
   Expected answer

   • conversion audit result
   • conversion points found
   • remediation
4. When the value crosses a system boundary, which annotations travel with it and which are critical?interoperability
   Expected answer

   • annotations carried
   • criticality flags
   • receiver obligations
   • behaviour when annotations are dropped
5. Which binding should be chosen for a newly modelled field, and on what test?decision
   Expected answer

   • decision test (does the moment shift with the observer)
   • chosen binding
   • reviewer
   • rationale

Artifacts

• Field binding declarationMachine-readable register of every temporal field exposed by the adopting Dimension with its binding, companion field requirements and validation rules.

A recurrence rule has a required frequency and optional interval, by-part filters, week start and a terminating count or until value, with count and until mutually exclusive. Expansion is anchored on the series start value, and by-position selection applies after the other filters, so an unanchored or unbounded rule is not evaluable without an explicit expansion window.

Questions

1. What frequency, interval and by-part filters define this rule, and in what order are they applied?definition
   Expected answer

   • frequency
   • interval
   • by-part filter values
   • evaluation order
   • by-position selection
2. What anchors the expansion, and does the anchor itself belong to the generated set?composition
   Expected answer

   • anchor value
   • anchor inclusion rule
   • anchor binding mode
3. Is the rule bounded by a count or by an until value, and does the until value match the anchor's value type and binding?constraint
   Expected answer

   • count
   • until value
   • value type match check
   • mutual exclusivity check
4. For an unbounded rule, what expansion window is used and who sets it?process
   Expected answer

   • window start
   • window end
   • window owner
   • re-expansion cadence
5. Which week start applies, and how does changing it alter the generated set?measurement
   Expected answer

   • week start value
   • affected by-part filters
   • divergence example
6. When the underlying zone rules change, are previously expanded instances recomputed or frozen?lifecycle
   Expected answer

   • recomputation policy
   • frozen instance marker
   • notification to dependents

Artifacts

• Recurrence rule expressionThe stored, portable expression of the rule together with its anchor, binding mode and expansion window.
• Expanded occurrence setMaterialised occurrences for a stated window, recording the zone and calendar data releases used so the expansion is reproducible.

A recurrence set is modified by excluded dates, additional dates and per-occurrence overrides keyed by the occurrence's original value; an override key that matches no generated occurrence yields an extra occurrence rather than an error. When expansion runs on a non-Gregorian scale, an explicit scale parameter selects the calendar and a skip parameter determines the treatment of dates that do not exist in the target year.

Questions

1. How is a single occurrence identified so that an override or cancellation can target it unambiguously?identity
   Expected answer

   • occurrence key value
   • key binding mode
   • behaviour when the key matches no occurrence
2. Which dates are excluded and which are added outside the rule, and who authorised each?exception
   Expected answer

   • excluded date list
   • added date list
   • authorising actor
   • reason
3. Which calendar scale governs expansion, and is it declared explicitly rather than inherited?classification
   Expected answer

   • recurrence scale key
   • declaration location
   • default when absent
4. What happens when a generated date does not exist in the target year — omit, move backward or move forward?constraint
   Expected answer

   • skip behaviour
   • default skip value
   • worked example for a leap-day rule
5. Do all consuming implementations expand this rule to the same set, and how was that verified?interoperability
   Expected answer

   • implementations tested
   • test vectors
   • divergences found
   • resolution
6. Are overrides preserved when the base rule is edited, and how are orphaned overrides detected?validation
   Expected answer

   • override reconciliation rule
   • orphan detection check
   • reporting surface

Artifacts

• Recurrence override setThe stored collection of exclusions, additions and per-occurrence patches for a series, with authorisation metadata.

A public holiday is a dated instance scoped to a jurisdictional division, carrying a title, the date actually observed, and notes recording substitution where the nominal date falls on a non-working day. Authoritative feeds publish a bounded forward horizon and include one-off holidays, so a holiday set is a per-jurisdiction, per-year assertion rather than a permanent rule.

Questions

1. Which jurisdiction or sub-jurisdictional division does this holiday apply to, and do divisions within the same state differ?spatial
   Expected answer

   • division identifier
   • parent jurisdiction
   • list of divisions where the holiday does not apply
2. Which authority proclaimed the holiday, and under what instrument?authority
   Expected answer

   • proclaiming authority
   • instrument type
   • instrument identifier
   • publication reference
3. Is the observed date the nominal date or a substitute, and what rule produced the substitution?composition
   Expected answer

   • nominal date
   • observed date
   • substitution rule
   • substitution note text
4. Does the holiday confer a non-working day, and for whom — all employers, public sector only, or specific sectors?classification
   Expected answer

   • day-off status
   • scope of application
   • sector exceptions
5. How far forward is the holiday calendar authoritatively published, and what is done beyond that horizon?temporal
   Expected answer

   • published horizon end date
   • beyond-horizon policy
   • estimated versus confirmed marker
6. How are one-off, rescinded or retroactively declared holidays recorded without corrupting historical calculations?lifecycle
   Expected answer

   • holiday status (recurring, one-off, rescinded)
   • effective instant
   • supersedes reference
   • recalculation policy for affected records

Artifacts

• Holiday calendar publicationThe authority's published holiday set for a jurisdiction over a stated horizon, retrieved and retained as evidence for downstream computation.
• Holiday proclamation instrumentThe legal instrument creating, moving or rescinding a public holiday.

An observance is a recurring day whose date is determined within a specific calendar system by a specific method — tabular rule, astronomical computation or local observation. The calendar registry itself distinguishes variants of the same tradition by determination method, which is direct evidence that a single canonical date frequently does not exist and that method and community must be recorded alongside the date.

Questions

1. Within which calendar system is this observance computed, and by which determination method?definition
   Expected answer

   • calendar key
   • determination method
   • computation reference
2. Is the observance fixed in its own calendar, movable, or dependent on observation that cannot be predicted?classification
   Expected answer

   • movability class
   • predictability horizon
   • fallback estimate rule
3. Which community or authority determines the date, and do communities in the same territory differ?provenance
   Expected answer

   • determining body
   • tradition or community
   • known divergent determinations
   • territory scope
4. What evidence supports the date asserted for a specific year, and when was it confirmed?evidence
   Expected answer

   • announcement source
   • confirmation instant
   • provisional versus confirmed status
5. Does the observance carry any civil effect, and where does that effect come from?authority
   Expected answer

   • civil effect flag
   • linked public holiday reference
   • instrument creating the effect
6. How does the system behave when a provisional date is later corrected?exception
   Expected answer

   • correction event record
   • downstream notification
   • recomputation scope

Artifacts

• Observance determination recordPer-year record of an observance's determined date, the determining body, the method applied and the confirmation status.

A working-day calendar is a composition of a territory's weekend rule and a jurisdiction's holiday set over a stated period, addressed by a named centre. A date-adjustment convention then determines how a date falling on a non-working day is moved; the standard conventions are following, modified following, preceding, modified preceding, nearest, a floating-rate variant, and no adjustment.

Questions

1. Which weekend rule and which holiday sets compose this calendar, and over what period is it valid?composition
   Expected answer

   • weekend rule reference
   • holiday set references
   • valid-from date
   • valid-until date
2. Which named centre or centres apply, and when several apply, is a date a working day only if it is one in all of them?process
   Expected answer

   • centre identifiers
   • combination rule (intersection or union)
   • worked example
3. Which adjustment convention applies, and does it respect month boundaries?decision
   Expected answer

   • convention code
   • month-boundary behaviour
   • direction of first attempt
4. How are day counts and deadlines computed — calendar days, working days, or working days with a cut-off time?measurement
   Expected answer

   • counting basis
   • cut-off time and its binding mode
   • inclusivity of the first and last day
5. What happens to previously computed deadlines when a holiday is added or moved after the fact?exception
   Expected answer

   • recomputation policy
   • frozen result marker
   • notification obligation
   • legal review trigger
6. Which reference-data releases were used to build this calendar, so a past computation can be reproduced exactly?provenance
   Expected answer

   • holiday feed snapshot reference
   • week data release
   • zone data release
   • build instant

Artifacts

• Working-day calendar projectionMaterialised list of working and non-working days for a centre and period, with the composing inputs and their release identifiers recorded.
• Date adjustment ruleThe declared convention, centre combination rule and counting basis applied by a given process or contract.

Temporal reference data is released as identified versions on an irregular, event-driven cadence — the zone database is released roughly twenty times a year and releases should be cryptographically signed. Distribution services support monolithic or per-zone versioning with synchronisation tokens and conditional requests, and some datasets carry hard expiry, so pinning a release and proving its freshness is a first-class obligation.

Questions

1. Which release of each reference dataset is currently pinned, and where is the pin recorded?identity
   Expected answer

   • zone data release identifier
   • locale data release identifier
   • leap table update marker
   • holiday feed snapshot reference
   • pin location
2. Was the release signature or checksum verified before adoption, and by whom?security
   Expected answer

   • verification method
   • key or checksum reference
   • verifier
   • verification instant
3. How is a change upstream detected, and how quickly must it be adopted?lifecycle
   Expected answer

   • change detection mechanism
   • polling or subscription cadence
   • maximum adoption lag
   • escalation path for urgent zone changes
4. Does any pinned dataset carry an expiry, and what is the behaviour after that instant?temporal
   Expected answer

   • expiry instant per dataset
   • pre-expiry warning threshold
   • post-expiry behaviour
5. Is versioning monolithic across all zones or independent per zone, and does the consumer handle both?interoperability
   Expected answer

   • versioning model
   • per-zone version support
   • synchronisation token handling
6. Can a historical computation be reproduced by re-pinning the releases it originally used?validation
   Expected answer

   • retained release archive
   • reproduction test result
   • gaps in retained releases

Artifacts

• Reference data release manifestThe set of pinned releases with publisher, release identifier, release instant, adoption instant and integrity evidence for every temporal dataset in use.
• Freshness attestationPeriodic record that each pinned dataset was checked, is unexpired, and is at or within the permitted lag of the current upstream release.

The maintainers of the primary zone dataset state plainly that many pre-1970 and future timestamps are wrong or misleading, that some entries derive from unreliable sources, and that transitions were often gradual rather than instantaneous. A downstream model must therefore carry an evidence class and known-inaccuracy marker with each fact, and must record where the stability-oriented locale layer and the volatile upstream layer disagree.

Questions

1. What is the evidence class of this temporal fact — legal instrument, authority publication, mirrored consensus, or reconstruction?evidence
   Expected answer

   • evidence class
   • citation
   • reconstruction method if applicable
2. Is the fact within a range the upstream maintainer declares unreliable, and is that warning propagated to consumers?quality
   Expected answer

   • reliability range flag
   • maintainer caveat text
   • consumer-facing warning surface
3. Where two authoritative sources disagree, which one governs here and on what documented basis?decision
   Expected answer

   • conflicting sources
   • governing source
   • decision rationale
   • decision maker
   • review date
4. When an upstream correction changes a historical value, what is done with results already published from the old value?exception
   Expected answer

   • correction event record
   • affected output inventory
   • reissue or annotate policy
   • notification obligation
5. Who is accountable for the accuracy of each class of temporal fact in this Dimension?ownership
   Expected answer

   • fact class
   • accountable role
   • review cadence
   • escalation contact
6. Is the provenance chain from legal instrument to mirrored dataset to local record complete and traversable?provenance
   Expected answer

   • chain completeness check
   • missing links
   • remediation action

Artifacts

• Data quality caveat registerRegister of declared unreliable ranges, source conflicts, governing choices and open corrections for temporal reference data.