I have been a long time user of Arch and recently, I wanted to update a single package on a set schedule. Here is how you can do it from a simple bash script:
# the next line updates the package database only
# the next line updates only a single package if it needs to be.
pacman -S –needed –noconfirm [package]
# if the package is a daemon, we will need to refresh and restart
systemctl restart [package]
Unfortunately, pacman does not support useful exit codes, so you can not only reload/restart the daemon if it’s been upgraded (at least, not yet). Pacman will always return 0 if the package is upgraded or not and will return a 1 if a true error occurs.