Hi all !
I have this problem explained in FileMaker Training Series for FileMaker 12 7-39
Be careful about holes in data series
When creating line or area charts to show a trend of data over time, be careful that there are no time periods missing from your chart, or else you may misinterpret the results. For instance, if you are charting sales volume by month and you had no sales at all for April, your chart will likely display March and May next to each other. Holes can be more easily filled if you are scripting to create a delimited list than if you need to rely on the completeness of the found set or a related set.
Anyone has an example of "scripting to create a delimited list of months"