How would a sysadmin calculate sysadmin day?

Question

Sysadmin day is the last Friday of July.

Sysadmins tend not to stray too far from the terminal, where they belong.

Sysadmins grok man {,/usr}/bin/*.

Sysadmins sometimes stray into interpreted languages found in /usr/bin/*.

Answer 1

This sysadmin came up with:

date -d $(date +%Y)-07-$(ncal -d $(date +%Y)-07-01 | awk '/^Fr /{print $NR;}') +'%F'

after @tuberous-potato's answer I came up with

echo $(date +%Y-%m)-$(ncal 7 $(date +%Y) | awk '/^Fr/ {print $NF}')

Answer 2

cal 7 $(date +%Y) | awk '{print $6}' | grep . | tail -n 1

Answer 3

Not exactly a one-liner, and building off the other answers - this one will get the next sysadmin day rather than just the one for this year.

#!/bin/bash

sysadmin_date() {
  year=$1
  echo $year-07-$(cal -h 7 $year | cut -d' ' -f6 | grep . | tail -1)
}

next_sysadmin_date() {
  this_years_sysadmin_date=$(sysadmin_date $(date +%Y))
  next_years_sysadmin_date=$(sysadmin_date $(expr $(date +%Y) + 1))
  today=$(date +%Y-%m-%d)

  [[ $today > $this_years_sysadmin_date ]] && echo $next_years_sysadmin_date || echo $this_years_sysadmin_date

  [[ $today == $this_years_sysadmin_date ]] && >&2 echo "Happy Sysadmin Day! "
}

next_sysadmin_date