ud

Which UNIX day is it today? ud can let you know!

UNIX days are calculated from the current UNIX time, which is the number of seconds since January 1st, 1970 at 00:00:00 UTC.

UNIX day 20000 is at 2024-10-04 (the 4th of October). It's a special day, since the next round (10000) UNIX day is 30000 at 2052-02-20.

This README.md file was written on UNIX day 19553 (which is 2023-07-15).

The ud utility can

• Output the UNIX day for today.
• Take a UNIX day and return the corresponding date.
• Take a date and return the UNIX day.

Build

With CMake and Make

cmake -B build -S . && make -C build

With gcc

gcc -std=c18 -O2 -D_GNU_SOURCE -o ud main.c

Install

On Linux, using sudo

sudo install -Dm755 ud /usr/bin/ud

On FreeBSD, using doas

doas install -d /usr/local/bin
doas install -m755 ud /usr/local/bin/ud

General info

• Version: 1.1.0
• License: BSD-3
• Authors: Alexander F. Rødseth <[email protected]> and Oliver Webb <[email protected]>