Docker Hub anonymous pull limit: Fixed or Rolling Window?

Hi,
I’d like to ask about the pull rate limits for anonymous users on Docker Hub.
I understand there’s a 6-hour limit, but could someone please clarify whether this is implemented using a Rolling (Sliding) Window or a Fixed Window rate limiting method?

You can have a specific number of pulls in any 6 hours period. Not like from 2 pm to 3 pm, so I assume that is what you mean by rolling.

Thank you very much for your helpful response.
I really appreciate your time and support!