check_overlaping_event.js

const moment = require('moment');

function dayDiff(d1, d2) {
  return Math.abs(moment(d2).diff(d1, 'days'));
}

const dateLen = {
  'day'  : 1,
  'week' : 7,
  'month': 31,
  'year' : 365
};

const checks = [
  dayDiff(moment(), moment().add(1, 'days')) >= dateLen.day;
  dayDiff(moment(), moment().add(1, 'days')) >= dateLen.week;
];

checks.map(res => res); // [true, false]