The GitHub Event API uses a `X-Poll-Interval` header for this purpose. There is also Retry-After but that seems more targeted towards error states.

EDIT: There is the `Cache-Control` header, it seems ideal for this use-case

- https://docs.github.com/en/enterprise-cloud@latest/rest/acti... - https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Re... - https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Ca...