Simple example to display Time ago from a Date in Swift

Date+TimeAgo.swift

extension Date {
    func timeAgoDisplay() -> String {

        let calendar = Calendar.current
        let minuteAgo = calendar.date(byAdding: .minute, value: -1, to: Date())!
        let hourAgo = calendar.date(byAdding: .hour, value: -1, to: Date())!
        let dayAgo = calendar.date(byAdding: .day, value: -1, to: Date())!
        let weekAgo = calendar.date(byAdding: .day, value: -7, to: Date())!

        if minuteAgo < self {
            let diff = Calendar.current.dateComponents([.second], from: self, to: Date()).second ?? 0
            return "\(diff) sec ago"
        } else if hourAgo < self {
            let diff = Calendar.current.dateComponents([.minute], from: self, to: Date()).minute ?? 0
            return "\(diff) min ago"
        } else if dayAgo < self {
            let diff = Calendar.current.dateComponents([.hour], from: self, to: Date()).hour ?? 0
            return "\(diff) hrs ago"
        } else if weekAgo < self {
            let diff = Calendar.current.dateComponents([.day], from: self, to: Date()).day ?? 0
            return "\(diff) days ago"
        }
        let diff = Calendar.current.dateComponents([.weekOfYear], from: self, to: Date()).weekOfYear ?? 0
        return "\(diff) weeks ago"
    }
}