when I export a gantt chart into a PDF, the first page shows the coloured bars on the paper. But already from the second page, the coloured bars are not visible because they would appear outside the paper sheet.
Would it be possible to “reset” the position of the timeline by moving it to the left so that the coloured bars would be visible on the page?
Unfortunately no, currently there are not many ways to control the printed output.
One thing you can try is changing the printed view-port by setting a different range of the time scale for the export.
The export service will print gantt using its current settings, so if you want to export a specific location of the timeline - you can set the timescale to display that part of the timeline only (using gantt.config.start_date/end_date configs), export gantt, and then set the time scale back to its original settings: