attempt-4.js

const LOCATIONS = { /* ... */ };
const LOCATION_NAMES = Object.keys(LOCATIONS);
const ALL_APPOINTMENTS = {};

console.log('🇸🇪💉 Info: Starting loop!');

let index = 0;
setInterval(() => {
    getAppointmentsForLocation(LOCATION_NAMES[index]);
    if (index === LOCATION_NAMES.length - 1) {
        index = 0;
        return;
    }
    index = index + 1;
}, 5000);

let hasInitialised = false;
setTimeout(() => {
    console.log('🇸🇪💉 Info: Assuming stable, will start sending emails now!');
    hasInitialised = true;
    const events = Object.keys(ALL_APPOINTMENTS).map(key => {
        ALL_APPOINTMENTS[key].key = key;
        return ALL_APPOINTMENTS[key];
    });
}, 120000);