Date extension

extension Date {
    
    func yearsCount(from date: Date) -> Int {
        return Calendar.current.dateComponents([.year], from: date, to: self).year ?? 0
    }
    
    func monthsCount(from date: Date) -> Int {
        return Calendar.current.dateComponents([.month], from: date, to: self).month ?? 0
    }
    
    func weeksCount(from date: Date) -> Int {
        return Calendar.current.dateComponents([.weekOfMonth], from: date, to: self).weekOfMonth ?? 0
    }
    
    func daysCount(from date: Date) -> Int {
        return Calendar.current.dateComponents([.day], from: date, to: self).day ?? 0
    }
    
    func hoursCount(from date: Date) -> Int {
        return Calendar.current.dateComponents([.hour], from: date, to: self).hour ?? 0
    }
    
    func minutesCount(from date: Date) -> Int {
        return Calendar.current.dateComponents([.minute], from: date, to: self).minute ?? 0
    }
    
    func secondsCount(from date: Date) -> Int {
        return Calendar.current.dateComponents([.second], from: date, to: self).second ?? 0
    }
    
    func timeAgo1(from date: Date) -> String {
        if yearsCount(from: date)   > 0 { return "\(yearsCount(from: date)) \(yearsCount(from: date) == 1 ? "year" : "years") ago" }
        if monthsCount(from: date)  > 0 { return "\(monthsCount(from: date)) \(monthsCount(from: date) == 1 ? "month" : "months") ago" }
        if weeksCount(from: date)   > 0 { return "\(weeksCount(from: date)) \(weeksCount(from: date) == 1 ? "week" : "weeks") ago" }
        if daysCount(from: date)    > 0 { return "\(daysCount(from: date)) \(daysCount(from: date) == 1 ? "day" : "days") ago" }
        if hoursCount(from: date)   > 0 { return "\(hoursCount(from: date)) \(hoursCount(from: date) == 1 ? "hour" : "hours") ago" }
        if minutesCount(from: date) > 0 { return "\(minutesCount(from: date)) \(minutesCount(from: date) == 1 ? "minute" : "minutes") ago" }
        if secondsCount(from: date) > 0 { return "\(secondsCount(from: date)) \(secondsCount(from: date) == 1 ? "second" : "seconds") ago" }
        return ""
    }
    
    func timeAgo(from date: Date) -> String {
        if yearsCount(from: date)   > 0 { return "\(yearsCount(from: date))y ago" }
        if monthsCount(from: date)  > 0 { return "\(monthsCount(from: date))M ago" }
        if weeksCount(from: date)   > 0 { return "\(weeksCount(from: date))w ago" }
        if daysCount(from: date)    > 0 { return "\(daysCount(from: date))d ago" }
        if hoursCount(from: date)   > 0 { return "\(hoursCount(from: date))h ago" }
        if minutesCount(from: date) > 0 { return "\(minutesCount(from: date))m ago" }
        if secondsCount(from: date) > 0 { return "\(secondsCount(from: date))s ago" }
        return ""
    }
}
let hour = 60 * 60
let day = 24 * hour
let week = 7 * day
let month = 9 * week
let year = 730 * day
let date = Date()

Date().timeAgo(from: Date().addingTimeInterval(-TimeInterval(year)))

extension Date {
    var timestampString: String? {
        let formatter = DateComponentsFormatter()
        formatter.unitsStyle = .abbreviated
        formatter.maximumUnitCount = 1
        formatter.allowedUnits = [.year, .month, .day, .hour, .minute, .second]
        return timeString?.formatter.string(from: self, to: Date()
    }
}