# Editing Driver Time Series

This article explains how to **edit driver time series** in Model Reef.

You will learn:

* Where to change driver values.
* How manual edits interact with imports and presets.
* How to keep driver edits auditable.

Driver time series are core assumptions that many variables depend on, so edits should be deliberate and traceable.

***

{% stepper %}
{% step %}

### Where to edit driver series

You edit driver values in:

* The **Driver Editor** grid for that driver.
* Sometimes in the Data Library, if you are editing an entry that is treated as a driver.

If the series is read only, it may be fully controlled by imports or restricted logic.
{% endstep %}

{% step %}

### Editing individual periods

To change a single period:

* Open the Driver Editor.
* Click the cell for the period you want to edit.
* Type the new value and press Enter.

The driver updates and all linked variables will recalculate automatically.
{% endstep %}

{% step %}

### Editing ranges of periods

You can adjust ranges by:

* Copying and pasting values across multiple periods.
* Using fill tools where supported.
* Pasting blocks of values from an external spreadsheet.

This is useful when you have a planned path for prices, volumes or growth that you want to drop in as a block.
{% endstep %}

{% step %}

### Interaction with imports and presets

If the driver is partly or fully imported:

* Historical segments may be read only if they are tied to external systems.
* Forecast segments may remain editable, allowing you to adjust the forward path.

If the driver is controlled by a preset:

* Some presets allow manual overrides of the resulting series.
* Others lock the series, requiring changes at the preset parameter level instead.

The editor will indicate which cells are editable.
{% endstep %}

{% step %}

### Keeping driver edits auditable

Because driver changes can affect many variables:

* Use notes to explain significant edits or structural changes in the time series.
* Tag important drivers so they appear in review workflows.
* Avoid making major changes without recording why they were made.

This helps reviewers and future you understand how the model evolved.
{% endstep %}
{% endstepper %}

***

## Related articles

* [Export Options](/syntax/chart-and-table-syntax/export-options.md)
* [Formula Editor Layout](/syntax/formula-syntax/formula-editor-layout.md)
* [Authentication (OAuth)](/help/xero-integration/authentication-oauth.md)
* [Build a Synergy & Integration Model](/how-tos/investment-and-transactions/build-a-synergy-and-integration-model.md)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://help.modelreef.io/syntax/drivers-syntax/editing-driver-time-series.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.