ctx.strokeStyle = color
    ctx.moveTo(x1, y1)
    ctx.lineTo(x2, y2)
    ctx.stroke()

def set_clock():
    # erase clock
    ctx.beginPath()
    ctx.fillStyle = "#fff"
    ctx.arc(width / 2, height / 2, ray * 0.89, 0, 2 * math.pi)
    ctx.fill()
    
    # redraw hours
    show_hours()

    # print day
    now = datetime.datetime.now()
    day = now.day
    ctx.font = "bold 14px Arial"
    ctx.textAlign = "center"
    ctx.textBaseline = "middle"
    ctx.fillStyle = "#fff"
    ctx.fillText(day, width * 0.7