bttf: A Command-Line Tool for Datetime Arithmetic, Parsing, and Formatting

Summary

A command-line tool called bttf (by BurntSushi) for datetime arithmetic, parsing, formatting, and related operations. The tool is dual-licensed under MIT or the UNLICENSE, and provides user documentation, sub-command help, and comparisons with similar tools. It supports printing the current time, custom formatting, and computing multiple relative times in a single command.