What's the problem this feature will solve?
Some old python apps wont work with the latest packages. Using this date parameter feature like the version number parameter feature would allow us to use some older apps that are no longer supported or being developed.

Describe the solution you'd like
Pip would look up the latest packages before a certain date or between two dates and only install packages up to that date or in that time span.

If you have an old app that only works with the old packages you can not run it now, but with this feature you could get all the necessary package versions to be able to use the app.

Alternative Solutions
The only other idea was to manually search for the right package versions but with many dependencies it would take a very long time.

Additional context
I would like to use the old nRF Connect for my Nordic Power Profiler Kit because the new one is missing a key feature I need.
The old one is written in python but it's not supported anymore.