Time Intelligence in Power BI Desktop
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.
When you create a model in Power Pivot or Analysis Services Tabular, you can apply the setting “Mark as Date Table” choosing a column of Date data type as the date in the table. You can have many date tables in a single data model and this setting affects both the metadata read by the clients (which can provide a particular user interface to manipulate a date selection) and the behavior of certain DAX expressions that manipulates filters in a date table.