CMPedometer data more than 7 days - ios

Question

I am trying to collect steps from CMPedometer for 10 days. It works fine for 7 days but returns 0 for last three days.
Here is the code:
var days:[String] = []
var stepsTaken:[Int] = []
let activityManager = CMMotionActivityManager()
let pedoMeter = CMPedometer()
var cnt = 0
override func viewDidLoad() {
super.viewDidLoad()
getDataForLast10Days()
}
func getDataForLast10Days() {
if(CMPedometer.isStepCountingAvailable()){
let serialQueue : DispatchQueue = DispatchQueue(label: "com.example.MyQueue", attributes: .concurrent)
let formatter = DateFormatter()
formatter.dateFormat = "d MMM"
serialQueue.sync(execute: { () -> Void in
let today = NSDate()
for day in 1...10{
let from = NSDate(timeIntervalSinceNow: Double(-7+day) ))
let hour = Calendar.current.component(.hour, from: from as Date)
let min = Calendar.current.component(.minute, from: from as Date)
let sec = Calendar.current.component(.second, from: from as Date)
let timeToSub = (hour * 60 + min) * 60 + sec
let fromDate = NSDate(timeIntervalSinceNow: (Double(-10+day) * (86400 ) ) - Double(timeToSub))
let toDate = NSDate(timeIntervalSinceNow: (Double(-10+day+1) * (86400) ) - Double(timeToSub))
let dtStr = formatter.string(from: (toDate as Date))
self.pedoMeter.queryPedometerData(from: fromDate as Date , to: toDate as Date) { (data : CMPedometerData!, error) -> Void in
//print("From Date: \(fromDate)","\n\n")
if(error == nil){
// print(data,"\n\n")
print("\(dtStr) : \(data.numberOfSteps)")
self.days.append(dtStr)
self.stepsTaken.append(Int(data.numberOfSteps))
}
}
}
})
}
}
But as the days increase since I have created the app, data increases for one day everyday. It's been 2 days since I created the app. It has data for 9 days and so on. How do I tackle this?
Please let me know what is wrong.

Answer 1

Everything is alright.
According to the method definition for the instance method queryPedometerData(from:to:withHandler:)
Only the past seven days worth of data is stored and available for you
to retrieve. Specifying a start date that is more than seven days in
the past returns only the available data.
See Apple's Documentation here.