Google Tasks node fails when setting Due date (Solution: force RFC 3339 format)

[rolandinsh]

Bug Description

Google Tasks return error 400 when adding dates (Due / Complete) via calendar selector:

How to fix? / Solution

Enforce RFC 3339 format: 2025-10-10T00:00:00Z. By typing it manually as formula/expression, everything works.

To Reproduce

Add Google Task Node (create or update).
Fill out title, task list and other fields.
Under "Update Fields" / "Additional Fields" select "Due Date" or "Completion Date".
Select date and time from calendar.
Send to Google API

Expected behavior

Correct Datetime format in RFC 3339.

Debug Info

{ "error": { "code": 400, "message": "Request contains an invalid argument.", "errors": [ { "message": "Request contains an invalid argument.", "domain": "global", "reason": "badRequest" } ], "status": "INVALID_ARGUMENT" } }

Other info:

1. Node type: n8n-nodes-base.googleTasks
2. Node version: 1 (Latest)
3. n8n version: 1.113.3 (Self Hosted)

Operating System

Ubuntu 24.04.3 LTS

n8n Version

1.113.3

Node.js Version

=22.16

Database

SQLite (default)

Execution mode

main (default)

Hosting

self hosted

[Joffcom]

Hey @rolandinsh,

Thank you for reaching out! We’ve received your issue and are looking into it. To help us track this internally, we’ve created a Linear ticket with the reference: "GHC-4776".

We’ll keep you updated as we make progress, but if you have any additional details or context to share, feel free to add them here - it’s always helpful!

Thanks for your patience and for bringing this to our attention.

[tushar-badlani]

@rolandinsh hope this pr fixes your issues

[n8n-assistant]

Hi @rolandinsh 👋

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[ ] I have updated to the latest stable version of n8n [please specify version number] and I am still experiencing this issue
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[n8n-assistant]

As we haven’t heard back from you, we’re going to close this issue to keep things organized. But don’t worry, if you have more information or need further assistance, you’re welcome to reopen the issue anytime or create a new one. We’re always happy to help!

Thanks for reaching out and have a great day! If this was closed by mistake and you have been waiting for us let me know and I can also re-open it.

[MilaJohannes]

I ran into the same problem when trying to set a Due date on task creation via the Google Tasks node (used through the new AI Agent / MCP tooling). The node kept throwing invalid argument errors whenever I passed a due value directly on Create, even though the date string looked fine.

As a practical workaround I ended up splitting the flow into two separate steps and letting the AI orchestrate them:

Create the task without any due date

MCP tool: Create_Task

Only passes the task title to the Google Tasks node

No additional fields, no due parameter at all

Ask the user for a reminder date and then update the task

After the Create step succeeds, the assistant confirms:
“I created the task <title> for you.”

Then it asks: “When do you want to be reminded about this task?”

The user can answer in natural language, e.g. “tomorrow”, “next week”, “3. April”, etc.

The AI converts that into a concrete date (relative to {{ $now }}) and calls a second MCP tool Update_Task (Google Tasks Update operation) using:

the task ID from the Create response

a Due_Date string in YYYY-MM-DD format, which the workflow then turns into a valid RFC 3339 timestamp before sending it to the API

The simplified prompt that drives this behaviour looks like this:

text
You are a helpful assistant.

When the user mentions a task they need to do, call the
"Create_Task" tool with only the task title.

After the tool call succeeds, confirm to the user in natural
language that the task was created.

Immediately afterwards ask when they want to be reminded
about the task. After their response, convert the natural
language date (e.g. "tomorrow", "next week", "3. April") to
YYYY-MM-DD using {{ $now }} as reference, and then call the
update tool to set the due date.

Always mirror the language of the user.
The time now is {{ $now }}.
This way Google Tasks never sees a due field on creation (which is where the error occurs), but setting or changing the due date via Update works reliably. Might be useful to document this pattern or consider handling the due date more leniently in the Create operation of the node.

Hope this helps people to save the hours I put in.