Don't include date into array if it is outside of date hours range

[taychris]

Hi all,
My desired array of objects should look something like this:
[ ... "2022-10-22T12:30", "2022-10-22T13:00", "2022-10-22T13:30", "2022-10-22T14:00", ... ]

I am working with:

• an timeInterval, example 30 (minutes)
• a startDate example "2022-10-22"
• an endDate example "2022-10-24"
• startTime example "08:00"
• endTime example "17:00"

My question is, how do I determine if the date time "2022-10-22T18:00" is outside of the desired range, so this date should not get pushed into the array, but "2022-10-23T08:00" and dates after should be added again.

What I have so far is:

    let appointmentStartFrom = startDate.concat("T", startingTime)
    let appointmentsEndAt = endDate.concat("T", endingTime)
    let hoursDifference = differenceInMinutes(parseISO(appointmentsEndAt), parseISO(appointmentStartFrom))
    //intervalToDecimal changes the interval time from string "00:30" to number 30 (minutes) 
    let intervalInMinutes = hoursToMinutes(intervalToDecimal(timeInterval))
    let appointmentsToCreate = hoursDifference / intervalInMinutes
    let appointmentsCreated = []

    if(Number.isInteger(appointmentsToCreate)) {
       for(var i = 0; i < appointmentsToCreate; i++) {
                appointmentsCreated.push(format(addMinutes(parseISO(appointmentStartFrom), intervalInMinutes * i), "yyyy-MM-dd'T'HH:mm"))
            }
     }

[fturmel]

This is a good use case for the each*OfInterval functions. I believe this should perform better since we are only creating datetimes that are within the correct time bounds with this approach.

https://date-fns.org/docs/eachDayOfInterval
https://date-fns.org/docs/eachMinuteOfInterval

import { eachDayOfInterval, eachMinuteOfInterval, lightFormat } from "date-fns";

// inputs
const intervalStepInMinutes = 30;
const startDateString = "2022-10-22";
const endDateString = "2022-10-24";
const startTimeString = "08:00";
const endTimeString = "17:00";

// parse time bounds to integers
const [startHours, startMinutes] = startTimeString
  .split(":")
  .map((v) => parseInt(v, 10));

const [endHours, endMinutes] = endTimeString
  .split(":")
  .map((v) => parseInt(v, 10));

// find all days in interval
const start = new Date(`${startDateString}T00:00`);
const end = new Date(`${endDateString}T00:00`);
const days = eachDayOfInterval({ start, end });

const results = [];

for (const day of days) {
  // create start and end datetime for each day
  const start = new Date(day.getTime());
  start.setHours(startHours, startMinutes, 0, 0);

  const end = new Date(day.getTime());
  end.setHours(endHours, endMinutes, 0, 0);

  // find 30 min intervals within time bounds
  const dailyResults = eachMinuteOfInterval(
    { start, end },
    { step: intervalStepInMinutes }
  );

  results.push(...dailyResults);
}

// convert resulting dates to desired string format
const formattedResults = results.map((d) =>
  lightFormat(d, "yyyy-MM-dd'T'HH:mm")
);

And here's a way to check the time range, per your original question and example.

import { differenceInMinutes, addMinutes, lightFormat } from "date-fns";

// inputs
const intervalInMinutes = 30;
const startDate = "2022-10-22";
const endDate = "2022-10-24";
const startingTime = "08:00";
const endingTime = "17:00";

const [startHours, startMinutes] = startingTime
  .split(":")
  .map((v) => parseInt(v, 10));

const [endHours, endMinutes] = endingTime
  .split(":")
  .map((v) => parseInt(v, 10));

const minutesLowBound = startHours * 60 + startMinutes;
const minutesHighBound = endHours * 60 + endMinutes;

const appointmentStartFrom = new Date(`${startDate}T${startingTime}`);
const appointmentsEndAt = new Date(`${endDate}T${endingTime}`);

const hoursDifference = differenceInMinutes(
  appointmentsEndAt,
  appointmentStartFrom
);

const appointmentsToCreate = hoursDifference / intervalInMinutes;

const appointmentsCreated = [];

if (Number.isInteger(appointmentsToCreate)) {
  for (let i = 0; i <= appointmentsToCreate; i++) {
    const date = addMinutes(appointmentStartFrom, intervalInMinutes * i);
    const minutes = date.getHours() * 60 + date.getMinutes();

    if (minutes >= minutesLowBound && minutes <= minutesHighBound) {
      appointmentsCreated.push(lightFormat(date, "yyyy-MM-dd'T'HH:mm"));
    }
  }
}