Diaries generally have the dates printed on their pages corresponding to the days of the year, organised by months or weeks, with a space to write notes and personal information of various kinds.
Diaries can also be completed with other additional information pages of various types, depending on the type of diary in question and for whom the diary is intended. The information, where appropriate, is very varied, some examples are: local saint's day, road maps, addresses and useful phone numbers, measurement converters, moon phases, etc.
The useful period of a diary is usually one year, although it can also be adapted to a specific school or sports calendar.
If the diaries are for school, aimed at children, it is advisable to use spiral plastic in manufacturing to avoid accidents.