# NotebookLM prompt: verifiable timeline

Source: https://nlmexporter.com/guides/prompts/timeline-extraction-prompt  
Section: Prompts  
Last verified: November 2026  
Plan: Free

Use it for history, case files, incident reviews and biographies. Paste the prompt below into the NotebookLM (Gemini Notebook) chat and replace the parts in square brackets. It tells NotebookLM to answer only from your sources, cite them and flag what they do not cover.

## Quick facts

| Item | Detail |
| --- | --- |
| Works in | NotebookLM / Gemini Notebook chat, and the customise box of Studio items |
| Sources needed | Sources that contain dated events. |
| Cost | Free to copy. Saving it in the extension is free for up to 10 plain prompts. |

## The prompt

```text
Build a timeline of [SUBJECT] as a table: Date | Event | Source and passage.
Keep the precision of the original: if a source says "spring 1998", do not turn it into a day.
Where sources give different dates for one event, show both. Do not state that one event caused another unless a source does.

Use only the sources in this notebook. Cite the source for every claim. If the sources do not cover something, say "not covered in the sources" instead of filling the gap.
```

## How to use it

1. Open the notebook and tick only the sources this question is about.
2. Paste the prompt into the chat and replace every part in [SQUARE BRACKETS].
3. Open two or three citations in the answer to confirm they say what the answer claims.
4. Save the answer as a note, then keep it: [Export the timeline to Excel](https://nlmexporter.com/guides/export/data-tables-to-excel).

## Adapt it

- Limit to a period or a person.
- Generate an infographic from the finished table.

> NotebookLM can misread or over-generalise a source. A prompt reduces that; it does not remove it. Check cited passages before you rely on an answer.

## Frequently asked questions

### What should be in the notebook before I use the verifiable timeline prompt?

Sources that contain dated events.

### Why does the prompt ask NotebookLM to say what is not covered?

Because a grounded tool is most useful when it shows the edges of your sources. An explicit instruction to flag gaps reduces confident answers that the sources do not support.

### Does this prompt work in Gemini Notebook?

Yes. Gemini Notebook is the new name of NotebookLM since July 16, 2026. The chat works the same way: it answers from the sources you select.

## Related guides

- [Export NotebookLM data tables to Excel](https://nlmexporter.com/guides/export/data-tables-to-excel)
- [NotebookLM prompt: glossary from your sources](https://nlmexporter.com/guides/prompts/glossary-from-sources-prompt)
- [NotebookLM prompt: compare sources in a table](https://nlmexporter.com/guides/prompts/source-comparison-table-prompt)
- [NotebookLM prompt: article outline from sources](https://nlmexporter.com/guides/prompts/article-outline-from-sources-prompt)
- [NotebookLM prompt: executive summary](https://nlmexporter.com/guides/prompts/executive-summary-prompt)
- [NotebookLM prompt: Zettelkasten notes](https://nlmexporter.com/guides/prompts/zettelkasten-notes-prompt)