Hi!

At this time, we don't allow modification of the expires_at parameter of collaborations through the API.

Depending on your use-case, you may be able to get away with leveraging shared links on the folder rather than collaborations and you can set the "unshared_at" date to automatically unshare the link on a certain date. You can add a shared link with expiration to a folder using a call similar to the below:

PUT /folders/folder_ID
-H Authorization Bearer BTOKEN]
-d {"shared_link": {"unshared_at": "DATE"}}

^ returns the shared link along with additional information about it bhttps://box-content.readme.io/reference#create-a-shared-link-for-a-folder]

Alternatively, you could put logic into your application to maintain the collaborations by adding and removing them with calls on specific dates - but at this time, you cannot set the expires_at parameter using the API.

Hopefully that helps!

-Tony

I am too looking at changing the expires_at using the API. This answer seems to be from over an year ago, and wonder if something changed. 

Looking at the API documentation, there is an expires_at property when updating a collaboration - https://docs.box.com/reference#edit-a-collaboration

I tried to use it, but the server consistently returns 500: Internal Server Error.  Also, if I use it on its own, I get a validation error that a "role" is required.

 Sorry for the confusion. There was an error in our documentation. The expires_at property can not be set from the API. As you mentioned, the role parameter is required. I updated the documentation to reflect the correct information for both of these things.