Analyzing dates in Power BI is quick and easy. There are just a few things you need to know to format dates.
When you drag a date field to an axis, it will automatically default to show year. However, you will have the option to drill down on your date field. In the top right of your visualization, you should see two down arrows. If you click those arrows, it will change your visualization to look at Quarter, if you click it again, you will see Month, then Day.
Determine Drill down Options
What options you have when you drill down is determined by the fields on your axis. If you do not want to give the option to drill down to day, click on the x next to Day and then you will no longer have the option to drill down to the day level.
I am sure you noticed that as you drilled down, you would see Quarter only, not Quarter and Year. If you want to expand your hierarchy, click on the next icon over.
When you are finished drilling down, click on the up arrow and you will be able to drill back up.
The last option for dates is to use to the exact date, instead of a hierarchy. If you go to the axis and click on the arrow next to your field name, you will have the option to change the field from Date Hierarchy to Date.
I hope this helps you get started in analyzing your time-series data in Power BI.