Automate Trello Card Creation from Google Calendar with n8n

1. Opening Problem Statement

Meet Angela, a project manager at a fast-paced cybersecurity firm. Every morning, Angela spends over 30 minutes sifting through her Google Calendar to identify important meetings she needs to track as actionable items for her team. Translating calendar events into Trello task cards is manual, repetitive, and prone to errors—leading to missed follow-ups and wasted time. Angela needs a way to automate this routine to focus more on project execution and less on administrative overhead.

This scenario is exactly what the n8n automation workflow we’re diving into solves. It eliminates manual entry of calendar events into Trello, ensures important meetings become actionable tasks, and reduces the chance of human error and task omissions.

2. What This Automation Does

When this n8n workflow runs automatically every day at 8 AM, it:

• Fetches all Google Calendar events scheduled for that day (from midnight to 11:59:59 PM).
• Ignores predefined recurring events such as “Lunch” or “Check email and start day” to avoid clutter.
• Creates Trello cards for each relevant calendar event, including meeting details, due dates, and a link to the calendar event.
• Structures Trello card descriptions with sections for meeting purpose, next steps, decisions made, and discussion topics for better team collaboration.
• Handles events individually to manage API limits and processing effectively.
• Runs unattended, freeing Angela from manual daily task creation.

This automation saves Angela over 30 minutes every day, prevents missed tasks from forgotten calendar events, and boosts team productivity by centralizing task management in Trello.

3. Prerequisites ⚙️

• n8n account (cloud or self-hosted) 🔌
• Google Calendar configured with OAuth credentials for read access 📅🔑
• Trello account with API token for writing cards 📋🔑
• Basic understanding of n8n workflows and credentials setup ⏱️

4. Step-by-Step Guide

Step 1: Set Up the Daily Trigger

Navigate to the Trigger Every Day at 8am Cron node. Configure it by clicking on the node → In the parameters panel, set the trigger time to 8:00 AM. This schedules your workflow to run daily at 8 AM, which suits typical workday start times.

Expected outcome: Workflow triggers exactly at 8 AM every day to start automation.

Common mistake: Forgetting to set the correct timezone in your n8n instance, leading to unexpected trigger times.

Step 2: Calculate Start and End of Day

Next is the Get Start & End of day Function node. Its JavaScript calculates the current day’s beginning (00:00:00) and end (23:59:59) timestamps. This time range defines which calendar events to fetch.

JavaScript code:

var curr = new Date;
var first = (curr.getDate());
var last = first;

var firstday = new Date(curr.setDate(first));
var lastday = new Date(curr.setDate(last));

beginning = new Date(firstday.setHours(0,0,0,0));
ending = new Date(lastday.setHours(23,59,59,99));

items[0].json.from = beginning.toISOString();
items[0].json.to = ending.toISOString();

return items;

This code sets from and to ISO strings, outputting them for the Google Calendar node.

Expected outcome: The workflow knows the daily window to query calendar events for.

Common mistake: Editing this code incorrectly can result in wrong date ranges and empty event results.

Step 3: Fetch Today’s Calendar Events

The Get Todays Events Google Calendar node uses the time range from the previous Function node to query all day’s events.

Navigate to Google Calendar node → Parameters → Set timeMin to ={{ $node["Get Start & End of day"].json["from"] }} and timeMax to ={{ $node["Get Start & End of day"].json["to"] }}. Ensure singleEvents is set to true to expand recurring events into single instances.

Expected outcome: You retrieve all individual events scheduled for today.

Common mistake: Not authenticating properly with Google Calendar OAuth2 API will lead to errors fetching events.

Step 4: Split Events Into Batches

The Split Events In Batches node breaks down the events list into smaller pieces (batch size 1), processing events one by one. This prevents hitting API or execution time limits.

Navigate to this node → Parameters → Set batchSize to 1.

Expected outcome: Each event is processed individually downstream.

Common mistake: Setting batch size too high could cause timeout or throttling.

Step 5: Define Trello Card Fields

The Set Trello Card Details node maps event details to fields that Trello requires for creating cards. It extracts the summary (title), description, due date from the event, and the calendar event URL.

Under Parameters → Values → Add strings:

• name: = {{$node["Split Events In Batches"].json["summary"]}}
• description: = {{$node["Split Events In Batches"].json["description"]}}
• duedate: = {{$node["Split Events In Batches"].json["start"]["dateTime"]}}
• URL: = {{$node["Split Events In Batches"].json["htmlLink"]}}

Expected outcome: Trello card data is prepared for creation.

Common mistake: Using field names that don’t match Google Calendar event properties results in empty Trello cards.

Step 6: Filter Out Recurring or Non-Actionable Tasks

The Remove Recurring Tasks IF node filters out common, repetitive tasks that don’t require Trello cards (e.g., “Lunch”, “Check email and start day”).

Set conditions to compare the event summary against a list of recurring summaries. If any match, the event is discarded.

Expected outcome: Only relevant meetings proceed to Trello card creation.

Common mistake: Failing to update the condition values when your calendar events naming changes causes irrelevant tasks to slip through.

Step 7: Create Trello Cards from Filtered Events

The Create Trello Cards node uses the prepared data to create cards in the assigned Trello board. It formats the description with meeting sections:

• Meeting purpose
• Next Steps
• Decisions Made
• Discussion

Navigate to Trello node → Parameters → Enter:

• name: = {{$node["Set Trello Card Details"].json["name"]}}
• description: a formatted template (as in the workflow JSON)
• due: = {{$node["Set Trello Card Details"].json["duedate"]}}
• urlSource: = {{$node["Set Trello Card Details"].json["URL"]}}

Expected outcome: Each relevant calendar event becomes a fully detailed Trello card.

Common mistake: Not having proper Trello API credentials causes card creation failures.

5. Customizations ✏️

• Customize Recurring Task Filter: In the Remove Recurring Tasks IF node, add or remove specific event names to tailor which tasks are filtered out, e.g., add “Daily Standup” to exclude it.
• Change Trello Description Template: Edit the description field in the Create Trello Cards node to include or remove sections relevant to your team’s workflow, such as adding “Links to Docs”.
• Adjust Event Fetch Time: Modify the Get Start & End of day Function node code to fetch events over custom time ranges (e.g., from 9 AM to 7 PM) to focus only on working hours.
• Add Notifications: Add extra nodes after card creation to send notifications to Slack or email whenever a new Trello card is made (requires integrating Slack or Email nodes).

6. Troubleshooting 🔧

Problem: “Google Calendar API returns error or empty response.”
Cause: OAuth credentials expired or misconfigured.
Solution: Go to credentials in n8n → Reauthorize the Google Calendar OAuth2 API. Double-check calendar email address matches your Google Calendar.

Problem: “Trello cards are not created despite workflow running.”
Cause: Incorrect Trello API token or board permissions.
Solution: Verify Trello API credentials in n8n, ensure proper board access. Test with a manual run using dummy data.

Problem: “Recurring tasks not filtered correctly.”
Cause: Condition values in IF node do not match event summary text exactly.
Solution: Update the event summary strings to match exact calendar event names or use regex for flexible matching.

7. Pre-Production Checklist ✅

• Verify all credentials (Google Calendar API, Trello API) are authorized and tested.
• Test the workflow manually with test events to confirm proper card creation.
• Check the IF node filtering logic for recurring events to avoid unwanted cards.
• Confirm the cron trigger time matches your desired timezone and work hours.
• Backup existing Trello board data before mass card creation (optional).

8. Deployment Guide

Activate the workflow in n8n by toggling it from inactive to active state. Ensure your n8n instance runs continuously or is hosted on a server that is always online to trigger at 8 AM reliably. Monitor execution logs daily initially for failures and errors.

For self-hosted n8n users, consider setting up monitoring tools and backup strategies to maintain uninterrupted automation.

9. FAQs

Q: Can I use an alternative calendar app instead of Google Calendar?
A: This workflow specifically uses Google Calendar’s OAuth API. For other calendar services, custom node development or API calls will be needed.

Q: Will this workflow consume Trello API rate limits?
A: Yes, but processing events in batches with a size of 1 helps manage rate limits carefully.

Q: Is my data secure in this setup?
A: Your credentials remain securely stored in n8n, and data transfer follows HTTPS and OAuth standard security protocols.

10. Conclusion

You’ve successfully automated the creation of Trello cards from your daily Google Calendar events. This workflow extracts only relevant meetings, ignores routine tasks, and formats cards to help your team stay aligned.

By freeing up to 30 minutes daily, you reduce manual errors and improve meeting follow-ups dramatically. Next, consider automating notifications to Slack when cards are created or linking Trello cards to deadlines in project management tools for end-to-end automation.

Keep experimenting with n8n’s versatile nodes to tailor your workflows further—making work less about managing tasks and more about delivering results.