Travel facts have a half-life.

Different facts age at different speeds

A landmark address may remain stable for years. Restaurant hours, construction, event access, and ticket inventory can change quickly. Treating both as equally fresh creates false confidence.

Assign a sensitivity level to the fact, not merely to the destination.

Use a checked-at date

“Current” is not inspectable. Record when the source was checked and which trip decision depends on it. That lets the system decide what needs another look as departure approaches.

Recheck by consequence

Prioritize facts whose failure would break the route: timed entry, final transport, closures, accessibility, and reservations. Lower-consequence inspiration can tolerate more uncertainty.

• Will failure break the day?
• Can the traveler verify it easily?
• Is there a usable fallback?

Put freshness in the report

Do not bury stale evidence in an internal database. Show the traveler what was checked, what changed, and what remains open. A departure checklist is the correct home for facts that cannot be safely frozen months ahead.

This is how an itinerary becomes a living operational document without pretending to be real-time.