cahhortega

    override func viewDidLoad() {
        super.viewDidLoad()
        dias[diaDaSemanaAtual].backgroundColor = UIColor.systemTeal
        dias[diaDaSemanaAtual].titleLabel?.font = .systemFont(ofSize: 13, weight: .semibold)
        calendario()
    }

cahhortega

lazy var dias: [UIButton] = [dom, seg, ter, qua, qui, sex, sab]

cahhortega

import UIKit

class ViewController: UIViewController {
    @IBOutlet weak var dom: UIButton!
    @IBOutlet weak var seg: UIButton!
    @IBOutlet weak var ter: UIButton!
    @IBOutlet weak var qua: UIButton!
    @IBOutlet weak var qui: UIButton!
    @IBOutlet weak var sex: UIButton!
    @IBOutlet weak var sab: UIButton!