using System;
using System.Threading;
using System.Windows.Forms;

namespace WindowsFormsApp2
{
    public partial class Form1 : Form
    {
        public Thread Working;
        public Form1()
        {
            InitializeComponent();
            Working = new Thread(new ThreadStart(ThreadActions));
            Working.Start();
        }
        private void ThreadActions()
        {
            while (true)
            {
                if (DateTime.Now.Hour == 8 && DateTime.Now.Minute <= 30 && !button1.Visible)
                    button1.Visible = true;
                else if (button1.Visible)
                    button1.Visible = false;

                if ((DateTime.Now.Hour == 12 && DateTime.Now.Minute >= 30 || DateTime.Now.Hour == 13) && !button2.Visible)
                    button2.Visible = true;
                else if (button2.Visible) button2.Visible = false;

                Thread.Sleep(2000);
            }
        }
    }
}