An example of a U.S. classified document; page 13 of a United States National Security Agency report on the USS Liberty incident, partially declassified and released to the public in July 2003. The original overall classification of the page, Top Secret code word UMBRA, is shown at top and bottom.
The Data Analysis Expressions (DAX) language is a formula language that allows users to define custom calculations in calculated columns and measures. DAX includes some of the functions that are used in Excel formulas, and additional functions that are designed to work with relational data and perform dynamic aggregation.
Date and Time Functions (DAX) Many of the date and time functions in DAX are very similar to the Excel date and time functions. However, DAX functions use a datetime data type, and can take values from a column as an argument. DAX also includes a set of time intelligence functions that enable you to manipulate data using time periods, including days, months, quarters, and years, and then build and compare calculations over those periods.