private def daysToTuple(days: Seq[Int]) : (Boolean, Boolean, Boolean, Boolean, Boolean, Boolean, Boolean) = {

    def iter(rest: List[Int], acc: (Boolean, Boolean, Boolean, Boolean, Boolean, Boolean, Boolean))
    : (Boolean, Boolean, Boolean, Boolean, Boolean, Boolean, Boolean) = rest match {
      case Nil => acc
      case (1 :: ds) => iter(ds, acc.copy(_1 = true))
      case (2 :: ds) => iter(ds, acc.copy(_2 = true))
      case (3 :: ds) => iter(ds, acc.copy(_3 = true))
      case (4 :: ds) => iter(ds, acc.copy(_4 = true))
      case (5 :: ds) => iter(ds, acc.copy(_5 = true))
      case (6 :: ds) => iter(ds, acc.copy(_6 = true))
      case (7 :: ds) => iter(ds, acc.copy(_7 = true))
    }
    iter(days.toList, (false, false, false, false, false, false, false))
  }