Based on wulkanowy/timetable-parser-php (not 1:1 copy)
Via NPM
$ npm install @wulkanowy/timetable-parser
import { Table } from '@wulkanowy/timetable-parser';
const table = new Table(/*Content of oXX.html file*/);
// This returns array of 5 arrays (for 5 days)
const lessons = table.getDays();
// This will log name of the second lesson on monday
console.log(lessons[0][1].subject);
// Get timetable title from the header
const title = table.getTitle();
console.log(title)
subject
groupName
teacher
className
room