handleDBReponse.js

const handleDBReponse = (response) => {
  const appointments = response;
  const today = moment().startOf("day"); //start of today 12 am
  const initialSchedule = {};
  initialSchedule[today.format("YYYY-DD-MM")] = true;
  const schedule = !appointments.length
    ? initialSchedule
    : appointments.reduce((currentSchedule, appointment) => {
        const { slot_date, slot_time } = appointment;
        const dateString = moment(slot_date, "YYYY-DD-MM").format("YYYY-DD-MM");
        !currentSchedule[slot_date]
          ? (currentSchedule[dateString] = Array(8).fill(false))
          : null;
        Array.isArray(currentSchedule[dateString])
          ? (currentSchedule[dateString][slot_time] = true)
          : null;
        return currentSchedule;
      }, initialSchedule);

  for (let day in schedule) {
    let slots = schedule[day];
    slots.length
      ? slots.every((slot) => slot === true)
        ? (schedule[day] = true)
        : null
      : null;
  }

  setSchedule(schedule);
};