How to construct the right datetime ranges for timezoned clients using Firestore?-CodePudding

I have a Cloud function that runs everyday, every 10 mins. It calculates some numbers regarding orders and customers for each restaurant branch.

Every branch has working hours, for example:

06:00 - 03:00 (24H) This means from 6:00 Tuesday to 3:00 Wednesday.

I made the function so that it handles the current day hours and whatever that is left of the previous day.

Tuesday(remaining 3 hours for Monday):
00:00 - 03:00
Tuesday:
06:00 - 23:59:59:999

Here's how the code handles generating the ranges:

const getRangeForOneDay = async (forPreviousDay = false) => {
  const lowerBound = "06:00"
  const upperBound = "03:00";


  const lowerBoundSplit = ["06", "00"];
  const startOfToday = new Date();
  startOfToday.setHours(
    forPreviousDay ? 0 : parseInt(lowerBoundSplit[0]),
    forPreviousDay ? 0 : parseInt(lowerBoundSplit[1]),
    0,
    0
  );


  const upperBoundSplit = ["03", "00"];
  const endOfToday = new Date();
  endOfToday.setHours(
    forPreviousDay ? parseInt(upperBoundSplit[0]) : 23,
    forPreviousDay ? parseInt(upperBoundSplit[1]) : 59,
    forPreviousDay ? 0 : 59,
    forPreviousDay ? 0 : 999
  );
  return [startOfToday, endOfToday];
};

const rangeToday = getRangeForOneDay(false);
const rangeYesterday = getRangeForOneDay(true);

const ranges = [rangeToday, rangeYesterday];

const branchId = "some real id";

for (const range of ranges) {
  const [startOfToday, endOfToday] = range;
  const orders = await admin
    .firestore()
    .collection("Orders")
    .where("branch_id", "==", branchId)
    .where("create_on", ">=", startOfToday)
    .where("create_on", "<=", endOfToday)
    .orderBy("create_on", "desc")
    .get();

  console.log(`Orders length = ${orders.size}`);
}

Here's how the ranges would look like:

Current Day(Tuesday):
From Date = 2022-11-08T06:00:00.000Z
To Date = 2022-11-08T23:59:59.999Z

Previous Day(Monday remaining hours data):
From Date = 2022-11-08T00:00:00.000Z
To Date = 2022-11-08T03:00:00.000Z

Both ranges are correct. You can see that the second range is for the previous day calculations, yet it takes place during the first 3 hours of the current day(Monday), which is also what I want.

My problem is that, for the second range, the query always returns 0. Despite creating an order between 12AM and 3AM Today(Tuesday) Nov 11th. The order I created was at 12:44:33 AM, but still it does not show up!

What am I doing wrong in the ranges?

I just want the code to work for this exact case. The normal case(first range), should work fine I think.

By the way, the timezone I am in is Toronto(-5). Though I don't think it matters since Firestore saves dates in UTC, just displays them on the Cloud Firestore in local timezone.

CodePudding user response：

The time ranges in output are in UTC (notice the Z instead of -05:00). If the time range is supposed to be Toronto time then you'll have to convert it first. Try using luxon and refactoring to code as shown below:

import { DateTime } from "luxon";

const getRangeForOneDay = () => {
  const today = DateTime.now().setZone("America/Toronto").startOf("day");

  return [
    [today.toJSDate(), today.plus({ hour: 3 }).toJSDate()],
    [today.set({ hour: 6 }).toJSDate(), today.endOf("day").toJSDate()],
  ];
};

The time ranges that you've mentioned are technically on the same day of your timezone or I renamed the var names above.

const ranges = getRangeForOneDay();
console.log('>>> ranges', ranges)

const branchId = "some real id";

for (const range of ranges) {
  const [startOfToday, endOfToday] = range;
  const orders = await admin
    .firestore()
    .collection("Orders")
    .where("branch_id", "==", branchId)
    .where("create_on", ">=", startOfToday)
    .where("create_on", "<=", endOfToday)
    .orderBy("create_on", "desc")
    .get();

  console.log(`Orders length = ${orders.size}`);
}

Now document with time 00:44 should fall in 00:00 - 03:00 UTC-5 time range.