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You saw a DAX time intelligence expression used in this example. First and foremost, we need to set a Date table in order to use time intelligence functions. We set a Date table in step 3 and selected a full date column as a date column. Note that you cannot use a column with the YYYYMMDD format; it should be a full date type column. Another important note about the date column is that it should contain all the dates from the beginning of the period to the end date of the period; if you have one day missed, you will see incorrect results in the time intelligence functions.

The TotalYTD function is used to calculate the YTD sales amount. Using this function is very simple; you just need to set the expression (SUM(InternetSales[SalesAmount] in this example) and then set the date column (Date[FullDateAlternateKey]), according to step 1. TotalQTD is very similar to YTD but with different usage.

TotalYTD can be used for the fiscal year as well; the only thing you need to do is to pass the last day of the year as the third parameter. In this example (step 7), June 30 is passed as the last day of the year, which means that TotalYTD will restart at July 1 each year.

Calculate is a function that works with this signature: Calculate (expression, filter1, filter2, and so on). This function will calculate the expression based on the filter context as a result of filters. In this example, the Calculate function is used to calculate the running total. There are many usages for the Calculate function; you can refer to some MSDN articles for more information about this function at http://technet.microsoft.com/en-us/library/ee634825.aspx.