Firebase Cloud Functions deletes nodes directly after rather than 24 hours later - node.js

Question

My goal is to delete all the message nodes 24 hours after they were sent using Firebase Cloud Functions and the Realtime Database. I tried copy and pasting the answer from this post however for some reason the messages delete directly after they were created rather than the 24 hours later. If someone could help me solve this problem I would really appreciate it. I have tried multiple different answers based on the same issue and they haven't worked for me.
Here is my index.js file:
'use strict';
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();
// Cut off time. Child nodes older than this will be deleted.
const CUT_OFF_TIME = 24 * 60 * 60 * 1000; // 2 Hours in milliseconds.
exports.deleteOldMessages = functions.database.ref('/Message/{chatRoomId}').onWrite(async (change) => {
const ref = change.after.ref.parent; // reference to the parent
const now = Date.now();
const cutoff = now - CUT_OFF_TIME;
const oldItemsQuery = ref.orderByChild('seconds').endAt(cutoff);
const snapshot = await oldItemsQuery.once('value');
// create a map with all children that need to be removed
const updates = {};
snapshot.forEach(child => {
updates[child.key] = null;
});
// execute all updates in one go and return the result to end the function
return ref.update(updates);
});
And my database structure is:

Answer 1

In the comments you indicated that you're using Swift. From that and the screenshot it turns out that you're storing the timestamp in seconds since 1970, while the code in your Cloud Functions assumes it is in milliseconds.
The simplest fix is:
// Cut off time. Child nodes older than this will be deleted.
const CUT_OFF_TIME = 24 * 60 * 60 * 1000; // 2 Hours in milliseconds.
exports.deleteOldMessages = functions.database.ref('/Message/{chatRoomId}').onWrite(async (change) => {
const ref = change.after.ref.parent; // reference to the parent
const now = Date.now();
const cutoff = (now - CUT_OFF_TIME) / 1000; // convert to seconds
const oldItemsQuery = ref.orderByChild('seconds').endAt(cutoff);
const snapshot = await oldItemsQuery.once('value');
// create a map with all children that need to be removed
const updates = {};
snapshot.forEach(child => {
updates[child.key] = null;
});
// execute all updates in one go and return the result to end the function
return ref.update(updates);
});
Also see my answer here: How to remove a child node after a certain date is passed in Firebase cloud functions?