By default, the results from the last 30 days are visible. In order to view results within another date range, use the date picker at the top of your results page. Select a date range on the overall Results page, click on the date button and choose from the options:
Last 7 days;
Last 30 days;
Last 12 months;
All time;
Custom.
Select 'Custom', in order to manually select a specific period:
Upon selecting a specific period, the dates will automatically update and the date range will be shown inside of the button:
You'll find the same date picker on top of your campaign specific results: