An issue has appeared with regards to dates in a couple of videos but I'll point to 10.05 FIRSTDATE & LASTDATE specifically. The LASTDATE function shows the last dates of the years as being 31/12/2009, 31/12/2010, 31/12/2011 and 30/12/2012. I'm presuming that it's because 2012 is a Leap Year, that it is showing the wrong date as being the last date in December. It seems to be an issue in both 2010 (which I'm working with) and 2013. Is there a way of dealing with this that I'm not aware of? - Thanks
Hi Moira,
The LASTDATE function returns the last date in the data set in the current context. The last date in the Power Pivot model for session 10 is 30/12/2012. There is no 31/12/2012 in the model. If there were it would return 31/12/2012.
Hope that makes sense.
Mynda
Ok, so it's the last date in December (of each year) that an order is made. Great, thanks 
