ITP Camp Dashboard converter to ICS

ITPCampICS.js

// 🪄 Experimental: Use at your own risk ✨
// Paste this into the Chrome developer tools console while you are in your dashboard page in list view
// It will either open your calendar or download an ics file, it works on my computer :)
// Read the code, and suggest improvements thanks.

let sessionsLists = document.querySelectorAll('#currentSessionsList .sessionListItem')

//Does not support events that end in the morning

let getEventData = event =>{
    let date = event.dataset.date
    let time = event.querySelector('.sessionInfo b').textContent.replace('am','').replace('pm','').split('-')
    let eventData;
        
    eventData = {
        eventName: event.querySelector('.sessionLeftColumn h3 a').textContent,
        date,
        time,
        location: event.querySelector('.sessionLeftColumn h3 a').href    
   }
   return eventData;
}

let getStartEndTime = (timeData) => {
    const tzOffset = (new Date()).getTimezoneOffset() / 60
    const [start, end] = timeData.map(time => time.split(':'))

    // TODO: Assumes that no event starts and ends in the morning
    if (Number(start[0]) < Number(end[0])) {
        start[0] = String(Number(start[0]) + 12);
    } 
    end[0] = String(Number(end[0]) + 12);
    // offset
    // start[0] = String(Number(start[0]) + tzOffset);
    // end[0] = String(Number(end[0]) + tzOffset);
    return {
        start: "T" + start[0].padStart(2,'0') + (start.length > 1 ? start[1].padStart(2,'0') : '00')+ '00',
        end: "T" + end[0].padStart(2,'0') + (end.length > 1 ? end[1].padStart(2,'0') : '00')+ '00',
    }
}

let getVEvent = (eventData) =>{
    if (eventData.time.length !== 2) 
        throw new Error('no time range in one of the events', eventData);
    const yearMonthDay = eventData.date.replaceAll('-','') 
    const time = getStartEndTime(eventData.time)
    return `
BEGIN:VEVENT
DTSTART:${yearMonthDay}${time.start}
DTEND:${yearMonthDay}${time.end}
DTSTAMP:20230608T225928Z
LOCATION:${eventData.location}
SUMMARY:${eventData.eventName}
END:VEVENT`
}

// Spread operator magic
const header = `BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//ical.marudot.com//iCal Event Maker
CALSCALE:GREGORIAN
BEGIN:VTIMEZONE
TZID:America/New_York
LAST-MODIFIED:20201011T015911Z
TZURL:http://tzurl.org/zoneinfo-outlook/America/New_York
X-LIC-LOCATION:America/New_York
BEGIN:DAYLIGHT
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
DTSTART:19700308T020000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU
END:DAYLIGHT
BEGIN:STANDARD
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
DTSTART:19701101T020000
RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU
END:STANDARD
END:VTIMEZONE`    
const footer = `
END:VCALENDAR
`
const ics = header + [...sessionsLists].map(getEventData).map(getVEvent).join('') + footer
console.log(ics)

window.open("data:text/calendar;charset=utf8," + escape(ics));