Give own calculated 'forecast' other layout in line chart

[MiKeZZa]

I have a line chart with 13 months in the dataset. 12 month from the past and 1 for the upcoming month. This is calculated data in our database. I want to plot these 13 months but make more clear that the last month is not actual information, but a forecast.

Is there a way to make a part of a graph dotted or something to make this clear?

[MalS · Accepted solution]

You can add a new field that indicates whether the data is an actual result or a forecast, then add that field to the Legend. One trick to doing this is that the actual data needs to end on the same date as the forecast starts, otherwise you end up with a gap in the line. See screenshot for details (March 2017 has an 'actual' value and a 'forecast' value).