As of iOS 17+, .labelsHidden() was all I needed to get the DatePicker alignment in the center.

DatePicker("", selection: $notificationTimeOnPicker, displayedComponents: .hourAndMinute)
.datePickerStyle(GraphicalDatePickerStyle())
.foregroundStyle(Color("ChartColor"))
.labelsHidden() // this solved my alignment issues caused by the default empty 'EmptyView' label that was hungrily taking up horizontal space.

I hope that solves it for anyone else looking for an answer in 2024!