Troubleshooting DateTime Configuration in n8n HTTP Node for Outlook Meetings

I’m using the HTTP node in n8n to create Outlook meetings because the native Outlook Meeting Node doesn’t allow adding attendees. My problem is that the meeting time isn’t being set properly, despite my DateTime values being in valid ISO format. I receive this error when using the following HTTP node body:

JSONCopied
{
  "subject": "{{ $json.subject }}",
  "body": {
    "contentType": "HTML",
    "content": "{{ $json.body.content }}"
  },
  "start": {
    "dateTime": "{{ $json.start.dateTime }}",
    "timeZone": "UTC"
  },
  "end": {
    "dateTime": "{{ $json.end.dateTime }}",
    "timeZone": "UTC"
  },
  "location": {
    "displayName": "Online"
  },
  "attendees": [
    {
      "emailAddress": {
        "address": "{{ $json.attendees[0].emailAddress.address }}",
        "name": "{{ $json.attendees[0].emailAddress.name }}"
      },
      "type": "required"
    }
  ],
  "isOnlineMeeting": false
}

The error returned is:

Bad request - please check your parameters
The value ‘{{ $json.start.dateTime }}’ of parameter ‘DateTime’ is invalid.

I tried converting the dateTime using the following code but encountered a similar error:

JSONCopied
{
  "subject": "{{ $json.subject }}",
  "body": {
    "contentType": "HTML",
    "content": "{{ $json.body.content }}"
  },
  "start": {
    "dateTime": "{{ DateTime.fromISO($json.start.dateTime).toISO() }}",
    "timeZone": "UTC"
  },
  "end": {
    "dateTime": "{{ DateTime.fromISO($json.end.dateTime).toISO() }}",
    "timeZone": "UTC"
  },
  "location": {
    "displayName": "Online"
  },
  "attendees": [
    {
      "emailAddress": {
        "address": "{{ $json.attendees[0].emailAddress.address }}",
        "name": "{{ $json.attendees[0].emailAddress.name }}"
      },
      "type": "required"
    }
  ],
  "isOnlineMeeting": false
}

The error then indicates:

Bad request - please check your parameters
The value ‘{{ DateTime.fromISO($json.start.dateTime).toISO() }}’ of parameter ‘DateTime’ is invalid.

My input DateTime is set properly in ISO format, for example: “2025-02-14T16:00:00Z”.

I’m also having trouble sharing my workflow. Copying nodes with CMD+C/CTRL+C and pasting them only transfers their setup rather than their full JSON configuration. When I attempt to paste the workflow as instructed:

BASHCopied
(Select the nodes on your canvas and use the keyboard shortcuts CMD+C/CTRL+C and CMD+V/CTRL+V to copy and paste the workflow.)

Please advise on resolving the DateTime format issue and the best method to share the workflow’s JSON. Any help or workflow examples would be appreciated.