> For the complete documentation index, see [llms.txt](https://docs.fabricplan.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.fabricplan.com/documentation/plan/planning-sheets/how-tos/forecast-data-to-predict-future-trends/extend-planning-beyond-source-data-periods.md).

# Extend planning beyond source data periods

Data input fields are essential for planning, where targets, adjustments, and key drivers are entered to define budgets, forecasts, and scenarios. Use the data input to enter values for current and historical periods available in the source data.

The **Extend Time** feature combines data input and forecasting to enable data entry beyond the periods available in the source data.

### Prerequisites

* The planning sheet must have at least one data input measure.
* Forecasts should not be created.

### Extend timelines for data input measures.

1. Select **Extend Time**.
2. Select the start and end periods to extend the data input measures to the specified time range.

<figure><img src="/files/kPsTubFkoyuNJDhXMuqq" alt=""><figcaption></figcaption></figure>


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