Is your feature request related to a problem? Please describe.

We would like to refine our URL blocks, by specifying a time range for the block, we we can limit access to a subset of the snapshots of URLs, rather than blocking the whole URL for all time.

Describe the solution you'd like

Support for a syntax like the embargo syntax, e.g. these two statements (which would have similar effects!):

org,httpbin)/ - {"access": "block", "url": "httpbin.org/", "before": "20201226"}
org,httpbin)/anything/something - {"access": "allow", "url": "http://httpbin.org/anything/something", "after":"202001226}

Describe alternatives you've considered

We could delete CDX records but we don't want to block the same URLs across all access contexts.

Additional context