Hello, I have a set of data that has the request number, the date the request was made, and the date the request was completed. What I need to do is to look back in history and to be able to see what the backlog of open requests was at a given period of time. So I want to see, at the end of each month/ week (whatever date series I choose), how many requests were still open. Can I use a calculated field in Tableau for this? I have attached my data set in Excel. Can anyone help me?