gistfile1.txt

    func setSelectedItemFromScrollView(_ scrollView: UIScrollView) {
        if calendarCollectionView == scrollView {
            let center = CGPoint(x: scrollView.center.x + scrollView.contentOffset.x, y: scrollView.center.y + scrollView.contentOffset.y)
            let index = calendarCollectionView.indexPathForItem(at: center)
            if index != nil {
                calendarCollectionView.scrollToItem(at: index!, at: .centeredHorizontally, animated: true)
                self.calendarCollectionView.selectItem(at: index, animated: false, scrollPosition: [])
                self.collectionView(self.calendarCollectionView, didSelectItemAt: index!)
                
                self.selectedDate = (index?.row)!
                self.selectedDateLabel.text = self.calendarArray?[(index?.row)!] as! String?
            }
            else {
            }
        }
    }