Provide access to lead conversion information in the API
According to Base support:
"Unfortunately access to lead conversion information is not something we support with our public API. Rest assured, you have not overlooked anything ;)"
This means that you lose the lead creation date when it is converted to a deal... so there is no way through the API to identify which leads converted last week (even though the info is clearly available in the funnel report)...
the apparent work-around is to create and populate a custom date field in the lead that is carried through to the deal but it seems like an unnecessary duplication of information already in the database.