Check if time range excludes a time

excludesTime.js

// You could play around with allowed inputs

import Moment from 'moment';
import { extendMoment } from 'moment-range';

const moment = extendMoment(Moment);

function excludesTime(start, end, when) {
  let startTime = moment(start, 'HH:mm');
  const endTime = moment(end, 'HH:mm');
  const whenTime = moment(when, 'HH:mm');
  if (startTime.diff(endTime) > 0) {  // in case start/end crosses midnight
    startTime = moment(startTime).add(-1, 'day');
  }
  return ! moment.range(startTime, endTime).contains(whenTime);
}

const start = '23:00';
const end = '01:00';

const restricted = '00:30';
const lateEnough = '01:30';
const earlyEnough = '23:30';
console.log(moment(start, 'HH:mm').format('hh:mma'), 'to', moment(end, 'HH:mm').format('hh:mma'), 'restricted time period', );
console.log(moment(restricted, 'HH:mm').format('hh:mma'), 'allowed?', excludesTime(start, end, restricted)); // false
console.log(moment(lateEnough, 'HH:mm').format('hh:mma'), 'allowed?', excludesTime(start, end, lateEnough)); // true
console.log(moment(earlyEnough, 'HH:mm').format('hh:mma'), 'allowed?', excludesTime(start, end, earlyEnough)); // trude