This addon has been renamed to a11y_datetime_addon and moved to a new repository:
👉 https://github.com/FriendsOfREDAXO/a11y_datetime_addon
Please install/update from there. This repository is archived and no longer maintained. See the 3.0.0 release notes and the CHANGELOG in the new repository for the full breaking-change summary, including the automatic migration for existing YForm fields.