If you want to conduct calculations, particular date calculations, you would be good to create a Date Table. This will allow you to use all of the time analysis calculations in DAX to their full extent. Now it is true that with the upgrades Microsoft continually roll out this isn't as necessary as it once was, but Date Tables are still relevant.
Now should you prefer a text based step by step guide to creating a date table then you can view our Date Table step by step tutorial.
If you want to follow along with the above video tutorial then you'll need to download the Power BI Date Table exercise file.