Easy to use add and remove days to a Date

DateExtension.swift

extension Date {
  
  /// Returns a Date with the specified days added to the one it is called with
  func add(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 subtract(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)
  }
  
}