Find your model's knowledge cutoff blind spot

A model answered a question about something recent as if it already happened, and it hadn't.

BeginnerRead 4 minDoing: under an hour5 steps

▶ Start

What you'll have at the end

A saved wrong guess about a recent event, and a rewritten prompt that gets the model to admit uncertainty instead

Before you start

You need

Direct access to a chat interface or API for the model you actually use, with any web-search or browsing tool you can switch off.

Not covered

Building an automatic system that flags every future stale answer on its own is a separate, bigger project; this gets you one verified example and a reusable line to paste in by hand.

Leans on

Find your target

Find the documented cutoff, skip the self-report
Confirm one real fact past that date

Catch the guess, then fix it

Ask cold, with no search, word for word
Add today's date and permission to not know

Make the fix outlast the chat

Save the wrong guess next to the fix

Where to go next

A model keeps hallucinating about a product it has never seen

go there when the gap is about a topic the model was never trained on at all, not a training date it fell behind

Checked 15 Aug 2026

Part of the Large Language Models (LLMs) cookbook