Hello everybody, I just encountered the case that I wanted to append to a monthly dataset from 1961m1 - 2021m10 new data from a file with the range 1960m1 - 2021m12. This was done using the GUI (menus), and failed. The command reference for "append" says: "One case that is not supported is where the new data start earlier and also end later than the original data. To add new series in such a case you can use the --fixed-sample option; this has the effect of suppressing the adding of observations, and so restricting the operation to the addition of new series." So I think what I'm asking for is a kind of tick box where I can activate the --fixed-sample option also in the GUI. thanks sven