Is there any way to make the columns regarding holiday periodes visible in the planning (different colour or highlight)?
I can only highlight the rows but cannot find a way to highlight periods of time (columns).
@lacaca It is not currently possible to customize the appearance of individual days in the Gantt chart - we do have an open feature request for this, which I’ll attach your post to!
That said, if holiday periods are marked as “Off Days” in Calendar View in your project, OmniPlan will automatically style them light grey (or whatever color you’ve selected for “Off-hours” in Styles view). If these days are not currently visible at all in the Gantt, you can enable them via View > Non-Working Time > Holidays.
Hope this helps!