Deadlines and calendar: pitfalls

Wrong forms, silent outcomes, diagnostics, typical mistakes of formalizers and AI agents, how to detect them. Items marked “confirmed by run” were reproduced during this research on the installed law (semantics law.core/0.2).

OverviewBoundariesCorpus formsPitfalls

1. Wrong start_count — a one-day mistake with no diagnostics (confirmed by run)

15.01 + 1 month: same_day → 15.02, next_day → 16.02. Both dates “look right”, there are no diagnostics — the mistake shows only against the text (“from the day” vs “from the next day”). In trials this is what gave the first red tests: the rule concluded, but not that date (NEITHER on the expected one). Detection: the directory’s second package (start-count/) pins both dates; in the corpus — a pair of cases on both sides of the boundary.

2. No month_end on a month step — MISSING_POLICY

31.01 + 1 month without month_end is a refusal, not “February’s last day”. The field is mandatory with calendar_month/calendar_year and read only by them (a field unrelated to the unit does not land in the trace). At the query result this is a MISSING_POLICY status with missing_inputs and the rule address. Detection: an edge test on the 31st is a mandatory neighbour of every monthly period.

3. Units do not mix — TYPE_ERROR

business_day on add_calendar_period and calendar units on add_business_days are type errors. The calendar_day unit is allowed in both terms deliberately: the operations differ (Nth counted day with roll vs fixed step), not the unit. Detection: read the term name, not the unit.

4. add_business_days without a snapshot — always a refusal

The calendar snapshot is always required: even with no_roll, even for calendar_day — the computation asks is_working_day. Zero nodes — MISSING_CALENDAR; two or more without a choice — AMBIGUOUS_CALENDAR; a date outside coverage — CALENDAR_OUT_OF_RANGE. Detection: the halal device — do not count without a calendar; take the number as a case fact instead.

5. Invented calendar — a mistake to the dangerous side

A “weekends-only” snapshot without holidays gives a period earlier than real. Counting business days without national and religious holidays is forbidden not by taste but by mistake direction (the halal comment). Detection: a snapshot without sourceArtifacts and coverage is a removal candidate, not a completion candidate.

6. Policy as a term argument — LDC-E2116 (confirmed by run)

Standard-term arity is 2; calendar and policy come via the environment, not as an argument. A trial with named arguments (after = …, count = …, policy = …) gave:

Output

error LDC-E2116: add_calendar_period: объявленная арность стандартного терма — 2; передано 6

plus LDC-E0201/LDC-E1330 on the names. Detection: positional call + deadline_policy Name; in the case context (inline — as with the French, or by profile — as with the medics).

7. cutoff outside the canon — DEADLINE_POLICY_INVALID

cutoff and the readable after_time are eight ASCII HH:MM:SS, hours 00–23, minutes/seconds 00–59. A bad cutoff is a policy refusal, a bad readable after_time — TYPE_ERROR; there is no silent normalization. Detection: always write time with seconds ("18:00:00", not "18:00").

9. Bare name as a deadline-window boundary — LDC-E2115

A window boundary is a value (a date, an instant, a rule variable, infinity/-infinity, a term with a policy), not a domain constant: window [moment, infinity) with an undeclared name is rejection LDC-E2115. A corpus floor instead of a bare name is [@0001-01-01, infinity) (see the duty pages).

8. Words after “bearer” — lowercase only

Write bearer/holder only as lowercase keywords.