Explanation
According to Microsoft Certified: Power BI Data Analyst Associate1, Power Query Editor is a tool that lets you connect to one or many data sources, shape and transform the data to meet your needs, then load that model into Power BI Desktop2.
One of the transformations you can perform in Power Query Editor is extract date from text, which creates a date value from a textual representation3. For example, given a text column like this:
Logged
2018-12-31 at 08:59
2019-01-01 at 09:15
You can extract the date part by using the Date.FromText function with a specific format4. The result will be:
Logged
Date
2018-12-31 at 08:59
2018-12-31
2019-01-01 at 09:15
2019-01-01
This makes it possible to use a built-in date hierarchy for analysis.