I'm trying to create a Tableau Worksheet that displays a dept., test code, grand total count for the codes, and a monthly count for the codes in a rolling month display whereby the month/year is in descending order (see 1st image below). I've been testing this using a relative date filter on the data source (see 2nd image below) but I'm not completely sure how this would work when running unattended on a schedule in production on a monthly basis. When this runs for this first time, e.g. 7/31/2016, I want it to populate that month and add to the grand total; when it runs for subsequent months, I want it to similarly populate that particular month and add to the grand total, etc. What I'm uncertain about is using Today as the anchor. If I create this on 7/31/2016, will Tableau "remember" that date moving forward thereby creating data columns for months July 2016 thru June 2017? If that's the case, with the range set for the next 12 months, when it gets to July 2017, will the months roll so that July 20016 drops off the display to be replaced by July 2017 and continue on in that fashion (oldest month drops off the end of the display as the new month is added to the beginning of the display)? What is the best way to create a 12 month rolling date range like this in Tableau? Thanks in advance.