Simple CLI date calculator
I needed to know the date of something that occurred 30 days prior to the UNIX timestamp value. Here’s how I did it.
First, I converted the UNIX timestamp using the GNU date command found in coreutils:
gdate is pretty flexible on input formats:
(nb: I used Homebrew to install GNU coreutils, and
it prefixed all the utilities with “g” to differentiate them from
their BSD equivalients. On GNU/Linux systems, regular
probably be used.)