"Short time ago" function for Swift (based on https://github.com/MatthewYork/DateTools)

shorttimeago.swift

    func shortTimeAgoSinceDate(date: NSDate) -> String {
        let calendar = NSCalendar.currentCalendar()
        let unitFlags = NSCalendarUnit.CalendarUnitMinute | NSCalendarUnit.CalendarUnitHour | NSCalendarUnit.CalendarUnitDay | NSCalendarUnit.CalendarUnitWeekOfYear | NSCalendarUnit.CalendarUnitMonth | NSCalendarUnit.CalendarUnitYear | NSCalendarUnit.CalendarUnitSecond
        let now = NSDate()
        let earliest = now.earlierDate(date)
        let latest = (earliest == now) ? date : now
        let components:NSDateComponents = calendar.components(unitFlags, fromDate: earliest, toDate: latest, options: nil)

        if (components.year >= 1) {
            return "\(components.year)y"
        } else if (components.month >= 1) {
            return "\(components.month)m"
        } else if (components.weekOfYear >= 1) {
            return "\(components.weekOfYear)w"
        } else if (components.day >= 1) {
            return "\(components.day)d"
        } else if (components.hour >= 1) {
            return "\(components.hour)h"
        } else if (components.minute >= 1) {
            return "\(components.minute)m"
        } else if (components.second >= 3) {
            return "\(components.second)s"
        } else {
            return "now"
        }
    }