You filter your analytics by date range using the Calendar button at the top right of your analytics pages.
Selecting the Calendar button displays a panel with a Date Range dropdown. Choose a preset range such as Last 90 Days, or enter a custom range. Once selected, the filter appears as a badge next to the Filters button.
The selected date range affects all data on the Performance, Content, and Audience pages. The date range filter is not available on the Overview page or the Episode Comparison page, and the range does not affect what those two pages show.
See also: Content Analytics · What do the Overview pages show? · How do I see my downloads over time?