get day difference between two dates swift

let cal = Calendar.current
let components = cal.dateComponents([.hour], from: date2, to: date1)
let diff = components.hour!

let calendar = Calendar.current

// Replace the hour (time) of both dates with 00:00
let date1 = calendar.startOfDay(for: firstDate)
let date2 = calendar.startOfDay(for: secondDate)

let components = calendar.dateComponents([.day], from: date1, to: date2)
return components.day