# Period Variance mode

{% hint style="info" %}
You must select a dimension to activate this mode; it is not available in Summary view. Only one measure can be used.
{% endhint %}

Period Variance mode allows you to compare time units within current and previous periods side-by-side, for example, months of this year vs. months of last year. It is effectively a combination of Period mode and Variance mode.

The following example uses Period Variance mode in the Sales database to analyze a customer's spending for the current month, compared with the previous month. You want to view the sales figures and the variance as a percentage.

1. Click the **Customer** dimension, select the customer (**Intercast Ltd**), then click the **Focus** button. The grid displays columns for the active properties (such as **Code** and **Name**) for that dimension, a **Total** column, and a column for each time unit in the current period.
2. Click **Period** > **Current month**. 
3. Click **Mode** > **Period Variance**. The grid updates to display a double-height header. The upper header displays the periods, the lower headers display current, previous, variance and % variance for each period.


---

# 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://docs.phocassoftware.com/analytics/customize-your-view-analytics/change-the-mode/period-variance-mode.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.