I want daily legacy/NRD 1 data ASAP. How do I know when there are data available?

Each legacy / NRD 1 data feed has an associated RSS feed in the data directory, in the "status" subdirectory, named "status/download_ready_rss.xml". Whenever a data set is complete and ready to be downloaded, an RSS message appears with a JSON text in its body to be machine-readable, e.g.,

{"data_feed": "domain_names_whois", "format": "regular_csv", "day": "2022-06-02", "available_from": "2022-06-03 01:34:20 UTC"}

In the subject line there is the same information in human readable format. This can be used to trigger download processes to get data ASAP.

Consult this blog for a hint for the implementation of scheduled downloading triggered by RSS.