BurntSushi released Biff, a Rust‑based CLI that handles datetime arithmetic, parsing, and formatting. The tool ships precompiled binaries for Windows, macOS, and Linux, and can be installed via cargo. It leverages Jiff for core logic and adds localization through ICU4X. Users can format timestamps, compute spans, and tag logs.

Unlike POSIX date, Biff focuses on RFC‑compliant formats and offers a strftime‑like syntax with wide compatibility. It supports locale configuration via BIFF_LOCALE, and can output time in any zone, round to minute precisions, or generate sequences of weekdays. The binary includes debug symbols to aid troubleshooting for users running scripts.

Installation is straightforward: cargo install biff-datetime-cli, optionally with the locale feature. Building from source requires a Rust toolchain. The project is dual‑licensed MIT or UNLICENSE, encouraging community contributions. Documentation encourages consulting biff --help or the detailed guide for advanced use cases in developer workflows or automation pipelines that require precise.

By exposing Jiff’s robust date‑time API on the command line, Biff offers developers a lightweight alternative to heavy scripting libraries. Its tagging feature can parse timestamps from logs, outputting JSON lines that integrate cleanly with downstream tools. The project remains in early stages, but its clear API and Rust foundation suggest rapid adoption.