Альберт Ушаков

const isWork = (start, end) => {
  if (!start || !end) {
    return false;
  }
  const startTime = moment(start, "kk:mm");
  const endTime = moment(end, "kk:mm");
  const isEndNextDay = endTime.isSameOrBefore(startTime);
  if (isEndNextDay) {
    endTime.add(1, "day");
  }
  return moment().isBetween(startTime, endTime, null, "[]");
};