EDIT: This was caused by using an old version uv (0.7.3) updating with `uv self update` to the latest version (0.11.2) resolved it. Original message below:

While the first form seems to work with `pyproject.toml`, it seems like the second form in the global `uv.toml` only accepts actual dates and not relative times. Trying to put a relative time (either in the form "7 days" or "P7D") results in a failed to parse error.