Daemonize server on MacOS!

I have a Mac Pro running Mac OS Sierra that I use as a server for a number of media-related things, including calibre. It works fine when the application is running interactively but I don't want/need the gui most of the time. The --daemonize switch appears to be a feature of the linux port but not MacOS for some reason. Is there ANY way to run the server in the background on MacOS?