Import events from one calendar into another

apps-script.gs

/**
 * Google Calendar Sync — Import events from one calendar into another.
 *
 * Copies upcoming events from a secondary calendar into your primary calendar
 * as private "Personal Appointment" blocks (title and times only). Keeps them
 * in sync: creates new blocks, updates moved events, and deletes stale ones.
 *
 * Setup:
 *   1. Replace SECONDARY_CALENDAR_ID with the calendar you want to import from.
 *   2. Add a time-driven trigger to run sync() on your preferred schedule.
 */

const SECONDARY_CALENDAR_ID = "your-email@gmail.com";
const BLOCK_TITLE = "Personal Appointment";

function sync() {
    const today = new Date();
    const endDate = new Date();
    endDate.setDate(today.getDate() + 7);
    const secondaryCal = CalendarApp.getCalendarById(SECONDARY_CALENDAR_ID);
    const secondaryEvents = secondaryCal.getEvents(today, endDate);
    const primaryCal = CalendarApp.getDefaultCalendar();
    const primaryEvents = primaryCal.getEvents(today, endDate);
    const primaryEventsFiltered = [];
    const primaryEventsUpdated = [];
    const primaryEventsCreated = [];
    const primaryEventsDeleted = [];
    Logger.log('Number of primaryEvents: ' + primaryEvents.length);
    Logger.log('Number of secondaryEvents: ' + secondaryEvents.length);
    for (const pEvent of primaryEvents) {
        if (pEvent.getTitle() == BLOCK_TITLE) { primaryEventsFiltered.push(pEvent); }
    }
    for (const evi of secondaryEvents) {
        let alreadyExists = false;
        for (const pEvent of primaryEventsFiltered) {
            const secondaryTitle = evi.getTitle();
            const secondaryDesc = evi.getDescription();
            if ((pEvent.getStartTime().getTime() == evi.getStartTime().getTime()) && (pEvent.getEndTime().getTime() == evi.getEndTime().getTime())) {
                alreadyExists = true;
                pEvent.setTitle(BLOCK_TITLE);
                pEvent.setDescription(secondaryTitle + '\n\n' + secondaryDesc);
                pEvent.setVisibility(CalendarApp.Visibility.PRIVATE);
                primaryEventsUpdated.push(pEvent.getId());
                Logger.log('PRIMARY EVENT UPDATED'
                    + '\nprimaryId: ' + pEvent.getId() + ' \nprimaryTitle: ' + pEvent.getTitle() + ' \nprimaryDescription: ' + pEvent.getDescription());
            }
        }
        if (alreadyExists) continue;
        if (evi.isAllDayEvent()) {
            continue;
        }
        //   else if ([1,2,3,4,5].includes(evi.getStartTime().getDay()))  // Uncomment for weekday-only sync.
        else {
            const newEvent = primaryCal.createEvent(BLOCK_TITLE, evi.getStartTime(), evi.getEndTime());
            // newEvent.setDescription(evi.getTitle() + '\n\n' + evi.getDescription());  // Uncomment to add a description.
            newEvent.setVisibility(CalendarApp.Visibility.PRIVATE);
            // newEvent.removeAllReminders();  // Uncomment if you don't want reminders for these imported events.
            primaryEventsCreated.push(newEvent.getId());
            Logger.log('PRIMARY EVENT CREATED'
                + '\nprimaryId: ' + newEvent.getId() + '\nprimaryTitle: ' + newEvent.getTitle() + '\nprimaryDescription: ' + newEvent.getDescription() + '\n');
        }
    }
    for (const pEvent of primaryEventsFiltered) {
        if (primaryEventsUpdated.indexOf(pEvent.getId()) == -1) {
            Logger.log(pEvent.getId() + ' deleted');
            primaryEventsDeleted.push(pEvent.getId());
            pEvent.deleteEvent();
        }
    }
    Logger.log('Primary events previously created: ' + primaryEventsFiltered.length);
    Logger.log('Primary events updated: ' + primaryEventsUpdated.length);
    Logger.log('Primary events deleted: ' + primaryEventsDeleted.length);
    Logger.log('Primary events created: ' + primaryEventsCreated.length);
}