Extensions for Swift's Date Type

DateExtensions.swift

extension Date {

    var isToday: Bool { return Calendar.current.isDateInToday(self) }
    
    /// Returns a Date with the specified days added to the one it is called with
    func adding(years: Int = 0, months: Int = 0, days: Int = 0, hours: Int = 0, minutes: Int = 0, seconds: Int = 0) -> Date {
        var targetDay: Date
        targetDay = Calendar.current.date(byAdding: .year, value: years, to: self)!
        targetDay = Calendar.current.date(byAdding: .month, value: months, to: targetDay)!
        targetDay = Calendar.current.date(byAdding: .day, value: days, to: targetDay)!
        targetDay = Calendar.current.date(byAdding: .hour, value: hours, to: targetDay)!
        targetDay = Calendar.current.date(byAdding: .minute, value: minutes, to: targetDay)!
        targetDay = Calendar.current.date(byAdding: .second, value: seconds, to: targetDay)!
        return targetDay
    }

    /// Returns a Date with the specified days subtracted from the one it is called with
    func subtracting(years: Int = 0, months: Int = 0, days: Int = 0, hours: Int = 0, minutes: Int = 0, seconds: Int = 0) -> Date {
        let inverseYears = -1 * years
        let inverseMonths = -1 * months
        let inverseDays = -1 * days
        let inverseHours = -1 * hours
        let inverseMinutes = -1 * minutes
        let inverseSeconds = -1 * seconds
        return add(years: inverseYears, months: inverseMonths, days: inverseDays, hours: inverseHours, minutes: inverseMinutes, seconds: inverseSeconds)
    }

}