index.js

require('dotenv').config()
const accountSid = process.env.TWILIO_ACCOUNT_SID;
const authToken = process.env.TWILIO_AUTH_TOKEN;
const client = require('twilio')(accountSid, authToken);
const cron = require('node-cron');
const moment = require('moment');

console.log(`Medication Reminder started at ${moment().format('DD/MM/YYYY HH:mm')}`);

// Trigger every day at 20h05 pm
cron.schedule('05 20 * * *', async () => {
  // Inital data of dates (start and end date)
  let startDate = '08/03/2022'

  // Reminds you during 20 days
  let endDate = moment(startDate, 'DD/MM/YYYY').add(20, 'days');

  console.log(startDate, endDate);

  // Set new dates for the new cycle
  if (moment().isAfter(endDate)) {
    for (let i = 0; i < 100000; i += 1) {
      if (moment().isAfter(endDate)) {
        // if 20 days have passed, set a pause for 7 days
        startDate = moment(startDate, 'DD/MM/YYYY').add(27, 'days').format('DD/MM/YYYY')
        endDate = moment(startDate, 'DD/MM/YYYY').add(20, 'days')
      } else {
        break;
      }
    }
  }

  // Send the reminder
  if (moment(startDate, 'DD/MM/YYYY').isBefore()) {
    client.messages
      .create({
        body: 'Take your medication',
        from: 'MEDREM',
        to: process.env.PHONE_NUMBER,
      })
      .then(message => console.log(message.sid));
  }
});