A tickler is often what refers to a tickler file system that is a paper or digital reminder system.
The tickler file system organizes a list of future or current tasks which need completed or tracked either once or on a recurring basis.
A tickler file system is often a set of 43 file folders that is used to organize time sensitive documents and tasks and acts as a future mailbox, that prompts you to take action on items that are at a specific date.
The tickler file system helps you to manage tasks as well as appointments and even documents which need attention in the future.
The physical tickler file system often consists of the 43 folders, 12 monthly folders and 31 daily folders.
A digital tickler file can be implemented using calendar applications or task management software with reminder features.
And items are placed into the folder that corresponds to the date they need your attention.
And each day, the folder for that date is accessed and the items within it are reviewed for any needed action.