cron

# install
pacman -S cronie

# enable at startup
systemctl enable cronie.service

# display jobs
crontab -l

# edit jobs
	MAILTO=your@email
	LOGFILE=/var/log/cron-pacman.log

	# 1. minute (0-59)
	# |   2. hour (0-23)
	# |   |   3. day of month (1-31)
	# |   |   |   4. month (1-12)
	# |   |   |   |   5. day of week (0-7: 0 or 7 is Sun, or use names)
	# |   |   |   |   |   6. commandline
	# |   |   |   |   |   |
	#min hr  dom mon dow command
	00   13   *   *   *  . /etc/profile && (echo; date; yes |pacman -Syuq) &>>$LOGFILE || (echo 'pacman failed!'; tail $LOGFILE; false)
	00   13   *   *   *  updatedb && date>>/root/done.txt

# use anacron
# write script inside .local/etc/cron.daily/

# run tasks every 5 minute
crontab -e
*/5  *  *  *  * runremindtask

# run tasks hourly
# place or symlink scripts inside /etc/cron.hourly
sudo chmod 777 scrip/path

# test if scripts placed inside /etc/cron.hourly works
run-parts --test /etc/cron.hourly

# giving your script an extension will make it invalid and result in the job not being run.
# [a-zA-Z0-9_-] are the valid characters, so the '.' makes it invalid.