Here Time Series Analysis does not mean calculating the YTD value of a numeric value. This is about discovering the clients who have been buying 10 days in a row and how concepts of time series analysis can be used with DAX. These are the requirements to have fun attending this session: a basic understanding of the Filter Context is required, this article has to be read at least once https://mdxdax.blogspot.com/2011/03/logic-behind-magic-of-dax-cross-table.html, and it's also helpful to have a good understanding of extended tables.