Four expiration categories at capture: 1 week / 1-6 months / 1-5 years / evergreen — standardize the decision to reduce cognitive load

Why This Is a Rule

Choosing a specific expiration date for every item (Tag time-sensitive information with explicit expiration dates at capture (expires:YYYY-MM-DD) — never rely on memory to track what is time-bound) creates decision friction: "Should this expire on March 15 or March 22? Or maybe April 1?" The precision is false — you don't actually know the exact day information will become stale. Four broad categories reduce the decision to a simple classification while providing enough granularity for meaningful differentiation.

1 week: Ephemeral information — meeting logistics, event details, temporary credentials, one-time instructions. Stale almost immediately after use. 1-6 months: Operational information — project status, current pricing, team assignments, quarterly plans. Changes with business cycles. 1-5 years: Structural information — role descriptions, company policies, technology architecture, long-term strategies. Changes slowly but does change. Evergreen: Timeless knowledge — principles, frameworks, mathematical relationships, human nature. Valid for decades (Mark genuinely timeless material as evergreen/no-expiry — principles and mental models don't need artificial expiration dates).

The categories are ordered by increasing review effort needed: 1-week items are processed and discarded quickly, 1-6 month items get monthly sweep attention, 1-5 year items get annual review, and evergreen items are set-and-forget. This tiered attention structure prevents over-maintaining durable items while ensuring ephemeral items don't silently linger.

When This Fires

• At the moment of capturing any information into your reference system
• When Tag time-sensitive information with explicit expiration dates at capture (expires:YYYY-MM-DD) — never rely on memory to track what is time-bound's expiration date assignment feels like an unnecessary precision exercise
• When building templates or intake forms for your knowledge management system
• Complements Tag time-sensitive information with explicit expiration dates at capture (expires:YYYY-MM-DD) — never rely on memory to track what is time-bound (expiration at capture) with the simplified decision framework

Common Failure Mode

Everything in the middle: classifying most items as "1-6 months" because it feels safe. This produces a large monthly sweep backlog and under-differentiates between ephemeral items (that should be 1-week and auto-purged) and structural items (that only need annual review). Use the full range of categories.

The Protocol

(1) When capturing an item, ask: "How long is this information valid?" (2) Classify into one of four categories: 1 week (meeting logistics, event details, temp credentials) → tag and let auto-expire or sweep weekly. 1-6 months (project data, current pricing, team status) → tag, sweep monthly (Monthly expiration sweep: review all past-due items, then archive expired ones and renew still-valid ones with fresh dates). 1-5 years (policies, architecture, long-term plans) → tag, sweep annually. Evergreen (principles, frameworks, mental models) → tag as no-expiry (Mark genuinely timeless material as evergreen/no-expiry — principles and mental models don't need artificial expiration dates). (3) When uncertain between adjacent categories, choose the shorter one (When uncertain about lifespan, expire at 3 months not 1 year — renewing valid items is cheap, but undetected stale information is dangerous). Better to renew a valid item than to miss a stale one. (4) Assign a specific date within the category: for "1-6 months," set a date 3 months out (the conservative default). For "1-5 years," set 1 year out. (5) The category determines the review cadence; the specific date determines when the item surfaces in the sweep.