Sysadmin

I was wondering how often does one choose to make and keep back ups. I know that “It depends on your business needs”, but that is rather vague and unsatisfying, so I was hoping to hear some heuristics from the community. Like say I had a workstation/desktop that is acting as a server at a shop (taking inventory / sales receipts) and would be using something like timeshift to keep snapshots. I feel like keeping two daily and a weekly would be alright for a store, since the two most recent would not be too old or something. I also feel like using the hourly snapshots would be too taxing on a CPU and might be using to much disk space.