Date Helpers

Date+Extensions.swift

extension Date {
    var age: Int {
        get {
            let calendar = Calendar.current
            let ageComponents = calendar.dateComponents([.year], from: self, to: Date())
            return ageComponents.year ?? 0
        }
    }
}

extension Date {
    func addMonth(n: Int) -> Date {
        let calendar = Calendar.current
        return calendar.date(byAdding: .month, value: n, to: self)!
    }
    
    func addYear(n: Int) -> Date {
        let calendar = Calendar.current
        return calendar.date(byAdding: .year, value: n, to: self)!
    }
    
    func addDay(n: Int) -> Date {
        let calendar = Calendar.current
        return calendar.date(byAdding: .day, value: n, to: self)!
    }
    
    func addHours(n: Int) -> Date {
        let calendar = Calendar.current
        return calendar.date(byAdding: .hour, value: n, to: self)!
    }

    var monthName: String {
        let calendar = Calendar.current
        let monthInt = calendar.component(.month, from: self)
        return calendar.monthSymbols[monthInt-1]
    }
    
    func months(from date: Date) -> Int {
        return Calendar.current.dateComponents([.month], from: date, to: self).month ?? 0
    }
    
    func startOfMonth() -> Date {
        return Calendar.current.date(from: Calendar.current.dateComponents([.year, .month], from: Calendar.current.startOfDay(for: self)))!
    }
        
    func endOfMonth() -> Date {
        return Calendar.current.date(byAdding: DateComponents(month: 1, day: -1), to: self.startOfMonth())!
    }
    
    func getFirstNonWeekendDate() -> Date {
        var nonWeekendDate = self
        let calendar = Calendar.current
        if calendar.isDateInWeekend(nonWeekendDate) {
            nonWeekendDate = nonWeekendDate.addDay(n: 1)
            if calendar.isDateInWeekend(nonWeekendDate) {
                nonWeekendDate = nonWeekendDate.addDay(n: 1)
            }
        }
        return nonWeekendDate.removeTimeStamp()
    }
    
    func removeTimeStamp() -> Date {
        guard let date = Calendar.current.date(from: Calendar.current.dateComponents([.year, .month, .day], from: self)) else {
            fatalError("Failed to strip time from Date object")
        }
        return date
    }
    
    func daysInMonths() -> Int {
        let calendar = Calendar.current

        let dateComponents = DateComponents(year: calendar.component(.year, from: self), month: calendar.component(.month, from: self))
        let date = calendar.date(from: dateComponents)!

        let range = calendar.range(of: .day, in: .month, for: date)!
        let numDays = range.count

        return numDays
    }
    
    /// Difference in seconds between two dates
    static func - (lhs: Date, rhs: Date) -> TimeInterval {
        return lhs.timeIntervalSinceReferenceDate - rhs.timeIntervalSinceReferenceDate
    }
}