Time: boundaries

What the construct does NOT do: limits, reserved values, neighbouring constructs and the selection rule.

OverviewBoundariesCorpus formsPitfalls

Does not do

• Not read the system clock. No axis is taken from the machine clock: the case sets decision_time, knowledge_time, legal_time and timezone explicitly, the scenario test — one per scenario. “Today” in a case is a date, not a call.
• Not add dates to magnitudes. Date + Quantity does not exist: a period is only a period step, a duration only a duration measurement. N months / N years are Quantity with a unit, not added to a date.
• Not measure months and years. days_between is calendar days (Integer, sign by argument order); hours and minutes — hours_between/minutes_between over Instant. Months and years are built by the period step, not measured.
• Not cover what time does not formalize. Closure also carries a window: outside the window it produces no negative — a repealed registry does not prove “no licence”.
• Not execute time @id. Dates have no separate identity: identity belongs to editions and events; time is a value.

Reserved and closed

• during, overlaps, before, after — RESERVED predicates (LDC-E2102).
• Duration, CalendarPeriod, BusinessPeriod — types without a constructor: a value comes only from measurement or a period step.
• Date without a timezone policy in an event — fatal TEMPORAL_RESOLUTION_POLICY_MISSING, not silent UTC: the zone choice changes event order and window hits.
• Event time precision is a microsecond: rounding to a second is forbidden; fractions of a second tell events and identity apart (EVENT_ID_CONFLICT).

Neighbours and the selection rule

• effective vs target window: norm applicability vs performance period. See the selection table in README.md.
• effective vs edition anchor: the rule’s own date vs the act’s date.
• days_between vs period step: measure a duration vs build a period (months/years).
• Date vs Instant: civil date vs offset instant; comparisons stay within kind.
• Fact-date comparison vs governs: case surface (corpus) vs JSON transport of the axis.