A personal organizer, day planner, or personal planner is a small book/binder, designed to be portable, usually containing a calendar, address book, and other sections usually including blank paper. It may also include pages with useful information, such as maps, telephone codes. It is related to the separate desktop stationery items that have one or more of the same functions, such as appointment calendars, Rolodexes, notebooks, and almanacs.
For some the function of paper-and-binder personal organizers, a 20th century innovation, is being assumed by electronic personal digital assistants (PDAs) and personal information manager software on personal computers. Some personal organizers attempt to bridge the gap by featuring holders for PDAs.