You can download these two sample chapters of the PowerPivot for Excel 2010: Give Your Data Meaning book:
- Chapter 2 – PowerPivot at Work
- This is introductive and suggested to read to anyone who is new to PowerPivot
- Chapter 7 – Date Calculations in DAX
- Do you want to make date calculation in DAX? This is the chapter for you: aggregations, comparisons, semiadditive measures, balance calculation by using transaction and much else.
Look at the download link in this page: http://www.sqlbi.com/books/powerpivot-for-excel-2010-give-your-data-meaning/
I suggest everyone to look at chapter 7 – date calculations in DAX are a very hot topic and many patterns are available and ready to use in that chapter!