As @Denrael mentioned, there are sample actions for monthly journals to the different services: Dropbox Journal action, iCloud Drive Journal action.
These do what you are asking for, except grouping by month, not day. To adjust these to write to journals that rollover by day, you would need to edit the template tag in the file name field of the action’s step. Instead of Journal-[[date|%Y-%m]].txt, you might want Journal-[[date|%Y-%m-%d]].txt. For details on modifying date format tags, take a look at the date section of the Using Templates article.