The default value of the 'from' date is determined by the latest commit in the 'code-tour' branch in the local copy of the dreamwidth repository, which is refreshed weekly.
As a guide to how up-to-date the local copy of the repository is, the last commit on 'main' according to this repository was made on 2024-04-08 21:25:49 -0500. The closer this date is to today, the better.
This script uses afuna's code tour generator, programmed in Python.