Ideally this would allow for totally arbitrary time periods (or at least arbitrary time periods that are whole numbers of hours, since 1-hour is the minimum time snapshot for long-term statistics afaik). At a minimum I’d really like to be able to use a weekly period for a lot of things. I actually tried to look through and figure out how a weekly period could be added, but it seemed like it needed changes to both the frontend and the backend and that seemed like a lot to take on.
I also found this issue related to the 5-minute period option that seems to be caused by the jump from short-term statistics to long-term statistics: Statistics Graph card: time span differs for "5 minute" & "hour" · Issue #13796 · home-assistant/frontend · GitHub