The following code doesn't compile and I'm not sure where to find the answers within Apple's documentation:
let birthdate = try currentHealthStore.dateOfBirthComponents()
var formatter = DateFormatter()
formatter.dateFormat = "dd-MM"
var formattedDate = formatter.string(for: birthdate)
self.ageValueLabel.text = birthdate
The error stems from the final line where it can't be converted to a string.
You are trying to assign a dateComponent value to label. But a label expects a String value. So yo just havr to do this.
self.ageValueLabel.text = formattedDate