BurntSushi/bttf: A command line tool for datetime arithmetic, parsing, formatting and more.

I use wolframalpha for most of my casual date ops etc. but the project is cool and I may need it.

But the most interesting bit is the documentation.

Quoting README:

I may ship arbitrary and capricious breaking changes at this point. You have been warned. […] And it doesn’t give a hoot about POSIX (other than the TZ environment variable).

And THIS. I either love it or hate it, can’t decide:

-h/--help
	This flag prints the help output for bttf.

	Unlike most other flags, the behavior of the short flag, -h, and the
	long flag, --help, is different. The short flag will show a condensed
	help output while the long flag will show a verbose help output.

It breaks my usual expectations but damn it’s a cool pattern that I really want to be a thing! You’re allowed to break conventions if your thing is really smarter and you’re explicit and intentional about it.