Woov (https://woov.com/) event timetable to ical. Designed to run in NodeJS, but can be adapted for browser if needed.

woov_timetable_2_ical.js

const fs = require('fs');
const { exit } = require('process');
const readline = require('readline');
const rl = readline.createInterface({ input: process.stdin, output: process.stdout });
const prompt = query => new Promise(resolve => rl.question(query, resolve));

const query = `
  query ($eid: ID!, $after: String) {
    event(eventId: $eid) {
      shows(first: 100, after: $after) {
        pageInfo {
          hasNextPage
          endCursor
        }
        edges {
          node {
            start
            end
            artists {
              name
              links {
                url
              }
              description
            }
            stage {
              name
              # description
            }
          }
        }
      }
    }
  }
`;

(async () => {
  var flat = [];
  let nextPage = true;
  let endCursor = null;
  const eventId = await prompt('enter your Woov Event ID (see Woov Invite link like https://gowoov.com/event/XXXXX): ');

  do {
    let body = JSON.stringify({
      query,
      variables: {
        eid: eventId,
        after: endCursor
      }
    })
    let response = await (
      await fetch('https://api.woov.nl/graphql',{
        method: 'POST',
        body,
        headers:{
          'Content-Type': 'application/json'
        }
      })
    ).json();

    if (response.errors) {
      throw new Error(response.errors[0].message);
    }
    nextPage = response.data.event.shows.pageInfo.hasNextPage;
    endCursor = response.data.event.shows.pageInfo.endCursor;
    flat.push(...response.data.event.shows.edges.map(e => e.node));
    console.log('loaded', flat.length, 'shows.')
  } while (nextPage);

  var ics = `BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
BEGIN:VEVENT
`;
  ics += flat.map(n => {
    let start = new Date(n.start);
    let end = new Date(n.end);
    let desc = n.artists[0].description ?? '';
    if (n.artists[0].links.length > 0) {
      desc += '\n\nLinks:\n';
      desc += n.artists[0].links.map(l => l.url).join('\n');
    }
    function icalDate(jsDate) {
      let result = '';
      result += jsDate.getFullYear().toString().padStart(4, '0');
      result += (jsDate.getMonth() + 1).toString().padStart(2, '0');
      result += jsDate.getDate().toString().padStart(2, '0');
      result += 'T' + jsDate.getHours().toString().padStart(2, '0');
      result += jsDate.getMinutes().toString().padStart(2, '0');
      result += jsDate.getSeconds().toString().padStart(2, '0');
      return result;
    }
    return `SUMMARY:${n.artists.map(a => a.name).join(' & ')}
DTSTAMP:${icalDate(start)}
DESCRIPTION:${desc.replace(/\r?\n/g, '\\n')}
DTSTART:${icalDate(start)}
DTEND:${icalDate(end)}
LOCATION:${n.stage.name}`;
  }).join(`
END:VEVENT
BEGIN:VEVENT
`);

  ics += `
END:VEVENT
END:VCALENDAR
`;
  fs.writeFileSync('timetable_2.ics', ics);
  console.log('done')
  exit(0)
})();