# Work With Time Intelligence

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#### Work With Time Intelligence

All data analysts will have to deal with time. Dates are important, so we highly recommend that you create or import a dates table. This approach will help make date and time calculations much simpler in DAX.

While some time calculations are simple to do in DAX, others are more difficult. For instance, the following screenshot shows what happens if you want to display a running total.

Notice that the totals increment for each month but then reset when the year changes. In other programming languages, this result can be fairly complicated, often involving several variables and looping through code. DAX makes this process fairly simple, as shown in the following example:

 YTD Total Sales = TOTALYTD ( SUM('Sales OrderDetails'[Total Price]) , Dates[Date] )

The YTD Total Sales measure uses a built-in DAX function called TOTALYTD. This function takes an argument for the type of calculation. You can use the SUM function to get the Total Price, as you’ve done throughout this module. The second argument that you want to operate over is the Dates field. You can use your Dates table and add this measure to your visual, and you’ll get the running total result that you’re looking for. You can use all functions with YTD, MTD, and QTD in a similar fashion.