I have data that returns a timestamp. I want to stride through these dates every 3 days – something like this. The issue is that the data I have is a string but I need it to be a Date object for the purpose of the chart. Can anyone advise the best way to approach this?

struct StockPrice: Identifiable {
    let id = UUID()
    let timestamp: String
    let price: Double
}

let stockPrices: [StockPrice] = [
    StockPrice(timestamp: "2018-06-22T19:29:37.000Z", price: 121.12),
    StockPrice(timestamp: "2018-06-23T19:29:37.000Z", price: 122.34),
    StockPrice(timestamp: "2018-06-24T19:29:37.000Z", price: 120.78),
    ...
]

struct ContentView: View {

let maxStockPrice = stockPrices.map { $0.price }.max()
let minStockPrice = stockPrices.map { $0.price }.min()

var body: some View {
    VStack {
        Chart(stockPrices) {
            AreaMark(
                x: .value("Month", $0.timestamp),
                yStart: .value("Total", $0.price),
                yEnd: .value("Total", minStockPrice ?? 0)
            )
        }
        .chartXAxis {
            AxisMarks {
                let dateFormatter = DateFormatter()
                if let value = $0.as(String.self) {
                    let _ = print(dateFormatter.date(from: value))
                    AxisValueLabel {
                        Text("T")
                            .fontWeight(.bold)
                            .foregroundColor(.white)
                    }
                }
            }
        }
    }
}