I have a graph of different film production stages over time, and want to show a vertical line across it showing today's date. I tried with today() expression, but it doesn't seem to work correctly.
Try adding a reference line. You can do that on the Presentation tab. You can use =today() as value for the reference line. You do need to set the time axis to continuous. This will usually show the dates as numbers, but you can change the format on the Number tab.
