Summary

The exclude-newer docs say

Accepts both RFC 3339 timestamps (e.g., 2006-12-02T02:07:43Z) and local dates in the same format (e.g., 2006-12-02) in your system's configured time zone.

But using the more concise/simpler date format:

[tool.uv]
exclude-newer = "2025-04-01"

Results in a warning being printed on every usage:

$ uv sync
warning: Failed to parse `pyproject.toml` during settings discovery:
  TOML parse error at line 18, column 17
     |
  18 | exclude-newer = "2025-04-01"
     |                 ^^^^^^^^^^^^
  failed to find time component in "2025-04-01", which is required for parsing a timestamp

The short version is simpler, more concise, and much easier for a human to type manually. The docs say that it is supported, so I suggest that a warning should not be printed.

Platform

macOS 15 arm64

Version

uv 0.7.8 (0ddcc19 2025-05-23)

Python version

3.11.11