Swift Charts picker to customize chart time

Question

I'm using Swift Charts to create a chart in my app, I want a scrollable view to be able to see chart data over a wide time range, however I am unable to properly get X axis labels to use the picker value (day, month, year)

ScrollView(.horizontal) {
                        Chart {
                            ForEach(filteredData) { item in
                                LineMark(
                                    x: .value("Date", item.day),
                                    y: .value("Measurement", item.value1)
                                    
                                )
                                .foregroundStyle(Color(measurementType.colour1))
                                .interpolationMethod(.catmullRom)
                                .symbol(by: .value("Measurement Type", measurementType.name))
}
}
}

The day values I'm using conform to Calendar.current.date

I tried using this for the line mark where timeUnits was a Calendar.Component selected by the picker

LineMark(
    x: .value("Date", item.day, unit: timeUnits),
    y: .value("Measurement", item.value1)                                
)

However, the actual chart values being incorrect then