---

name: heuristic-numbers-and-dates-double-check
description: Use as a mandatory post-draft quality pass on any legal document or advice output. Requires a dedicated review of every number and date in the output — statute article numbers, case citations, deadlines, limitation periods, currency amounts, percentages, and Hijri/Gregorian dates. AI legal drafting errors are most visible and most damaging when they involve incorrect numbers; this heuristic prevents those failures. Applies universally across all jurisdictions and document types.
license: MIT
metadata:
id: heuristic.numbers-and-dates-double-check
category: heuristic
priority: P0
intent: [core, quality-control, numbers, dates, accuracy, post-draft]
related: [heuristic-statute-of-limitations-flag, heuristic-party-names-consistency, router-confidence-scorer, heuristic-always-state-jurisdiction-first]
source: Louis — HAQQ Legal AI (github.com/sboghossian/mini-claude-for-legal)
version: "1.0"

Double-Check Numbers and Dates

When this applies

This heuristic runs as a post-draft pass on every substantive legal output: contract drafts, review memos, advice letters, litigation analysis, regulatory summaries. Numbers and dates are the most failure-prone category in AI-generated legal text, and errors in this category are the most damaging — they directly affect legal rights, deadlines, and financial obligations.

Apply this pass after drafting and before delivering any output to the user.

What to check

1. Statute and regulatory article numbers

• Do not invent article numbers. If the applicable article is not known with certainty, state the concept and note that the exact article number should be verified.
• If an article number was provided in the user's input or a reliable source, reproduce it exactly.
• Common failure mode: hallucinated article numbers that resemble real ones (e.g., "Art. 347 COC" when the correct article is Art. 349).
• MENA context: article numbers in Lebanese, UAE, KSA, and Egyptian codes are frequently cited in practice; errors here undermine credibility immediately.

2. Case citations

• For any case citation, verify: year, docket or reference number, court, paragraph pin-cite (if used).
• Do not invent case citations. A fictional case citation in a legal memo is a serious professional error.
• If only the case name and general principle are known, state the principle without a fabricated citation: "The general principle from X case (verify citation with a legal database) is…"
• MENA context: DIFC and ADGM judgments use specific reference formats (e.g., "CFI-2024-XXXXX"). KSA court decisions are often not publicly cited by docket number. Lebanese Court of Cassation decisions are cited by chamber and date.

3. Deadlines, notice periods, and limitation periods

• Deadlines embedded in legal advice must be verified against current law. Limitation periods change by legislation; notice periods differ by contract and statute.
• Specify: (a) the period, (b) the start date (accrual event), (c) the end date, and (d) whether the period is calendar days or business days.
• Flag immediately if a limitation period is within 6 months (see [[heuristic-statute-of-limitations-flag]]).
• MENA context: MENA jurisdictions mix calendar-day and business-day conventions. UAE commercial contracts often use business days; UAE court deadlines often use calendar days. KSA may use Hijri calendar for official deadlines — confirm the calendar being used.

4. Currency amounts

• Specify the currency with its ISO code (USD, AED, SAR, LBP, EGP, EUR, GBP). Do not rely on symbols alone, especially in bilingual documents.
• Do not drop zeros. AED 1,000,000 and AED 1,000 are very different numbers; a dropped zero is a contract defect.
• Check that amounts are consistently expressed across the document (amount in figures = amount in words = amount in schedules).
• MENA context: Lebanon's Lebanese pound (LBP) has been subject to multiple exchange rates; specify which rate applies if relevant. KSA transactions may reference SAR and USD simultaneously; confirm which is controlling.

5. Dates (calendar and Hijri/Gregorian)

• Check all dates for internal consistency (e.g., a contract executed on 1 January cannot reference events that happen on 15 December of the same year as having already occurred).
• In KSA documents, dates are often stated in both Hijri and Gregorian calendars. Verify that both match. Conversion errors between calendars are common — use a verified converter.
• In UAE, official government documents may use Hijri; commercial contracts use Gregorian. If the document is for a UAE government entity, check whether the execution date and effective date should be expressed in Hijri.
• Execution vs effective date: many documents are executed on one date but become effective on another. Both must be stated; they must be logically consistent.

6. Percentages and rates

• Interest rates, profit rates (for Islamic finance structures), ownership stakes, and tax rates must be stated accurately.
• In KSA and UAE Islamic finance: conventional interest rates do not appear; profit rates and rental yields should be stated as percentages and verified against the transaction documents.
• Ownership stakes in company structures must add up to 100%. A cap table with stakes totaling 99% or 101% is a drafting error.

The checking tactic

After producing a draft, run a dedicated "numbers and dates only" review pass:

1. List every number and date in the output — scan systematically, clause by clause.
2. For each item: confirm it is intentional, verify (or flag for verification) against source material.
3. Flag uncertainties: if a number was not provided by the user and was generated by inference, state it explicitly: "Note: the limitation period stated above (3 years) is based on general UAE Civil Code provisions; verify against the specific contract type and current law."
4. Consistency check: for multi-document transactions, verify that amounts, dates, and references are consistent across all documents.

Lebanon example (civil-law deadlines)

Lebanon's Code of Obligations and Contracts (COC) provides indicative limitation periods:

Claim type	Period	Reference
Tort	3 years	Art. 257 COC
Commercial contracts (general)	10 years	Art. 349 COC

These periods are jurisdiction-specific and subject to legislative change. Verify against current law rather than relying on these as authoritative. Shorter periods may apply to specific claim types (insurance: 2 years; maritime: 1 year; wage claims: 1 year).

The principle is the same for all MENA jurisdictions: always verify rather than recall.

Failure modes

Failure	Impact
Incorrect limitation period stated	User may miss filing deadline; case may be time-barred
Fabricated article number cited	Embarrassment; advice relying on non-existent provision
Currency amount with dropped zero	Contract defect; potential financial loss
Hijri/Gregorian conversion error	Incorrect effective dates; missed deadlines
Wrong percentage for ownership stake	Corporate structure documents are legally defective

Related skills

• [[heuristic-statute-of-limitations-flag]]
• [[heuristic-party-names-consistency]]
• [[router-confidence-scorer]]
• [[heuristic-always-state-jurisdiction-first]]