Get the length between two dates in hours

Question

I am reading sleep data into my react-native app using react-native-healthkit, and I need to find a way to get the total amount of sleep time. The data is read in like this:

If anyone has any ideas on the best way to handle this data, please let me know.

Answer 1

extension Date {

    /// Hours since current date to given date
    /// - Parameter date: the date
    func hours(since date: Date) -> Int {
        let calendar = Calendar.current
        let dateComponents = calendar.dateComponents([.hour], from: self, to: date)
        return dateComponents.month ?? 0
    }
}

date2.hours(since: date1)

Using .timeIntervalSince is a bad practice, because some hours may be shorter than other.