@eprostko The issue is that modeOptions is not a valid configuration field in MMM-CalenderExt2. Where did you get that?
weekStart needs to be set directly inside the view object:
views: [
{
position: "top_bar",
mode: "week",
type: "row",
weekStart: 0, // ← here, at the top level of the view
slotMaxHeight: "150px",
slotCount: 3,
// ...
}
]
The top-level weekStart: 0 in your config has no effect either - there’s no such top-level option, only the per-view (or defaultSet.view) one.