Breaking changes to projects API preview and webhook date format

The format of the created_at and updated_at fields in the projects API preview and project webhook payloads is being changed to be consistent with the standard YYYY-MM-DDTHH:MM:SSZ ISO 8601 format used by all other APIs and webhooks.

Previously project webhook payloads would include these fields as an integer number of seconds:

  "action": "created",
  "project_card": {
    "created_at": 1503590773,
    "updated_at": 1503590773

And project APIs would include these fields with milliseconds that were always zero:

  "url": "",
  "id": 1002604,
  "created_at": "2017-08-24T15:56:15.000Z",
  "updated_at": "2017-08-24T15:56:15.000Z"

Starting on Monday October 2nd, 2017 these fields will be returned as YYYY-MM-DDTHH:MM:SSZ formatted strings in all projects APIs and project, card, and column webhook payloads.

You can opt-in to this change in the project APIs today by using the following Accept header that will enable the new format before it becomes the default:


We apologize for any inconvenience this causes you.

If you have any questions or feedback, please let us know.