In Power BI Desktop (as of February 2016) you have to use DAX to apply calculations over dates (such as year-to-date, year-over-year, and others), but you do not have the Mark as Date Table feature. This article describes which scenarios are impacted and the possible workarounds.
You might have used FIRSTNONBLANK and LASTNONBLANK in semi-additive measures, but you might not be aware that their use is not limited to time intelligence functions. This article shows alternative scenarios where these functions are useful.
This article describes how to implement a custom year-over-year calculation in DAX based on arbitrary associations between different periods. As an example, we describe the comparison of the 53rd week in a ISO Calendar.
Computing the rolling 12-month average in DAX looks like a simple task, but it hides some complexity. This article explains how to write the best formula avoiding common pitfalls using time intelligence functions.
Values such as inventory and balance account, usually calculated from a snapshot table, require the use of semi-additive measures. In Multidimensional you have specific aggregation types, like LastChild and LastNonEmpty. In PowerPivot and Tabular you use DAX, which is flexible enough to implement any calculation, as described in this article.
The DAX language provides several Time Intelligence functions that simplify writing calculations such as year-to-date (YTD), year-over-year (YOY) and so on. However, if you have special calendar structure such as 4-4-5 weeks’ calendar, you need to write your custom time intelligence calculation. In this article, you will learn how to