Scheduling software or schedulers are used to set and document start and end dates for the execution of tasks (To Do's). Schedulers are of high importance in the whole business environment - especially in companies of the manufacturing industry as well as in service providers in the context of project management and last but not least in medical practices as well as in clinics. Appointment scheduling is closely related to project management. Project-related appointments are managed and the working hours or the duration of a work step are recorded. These values can be used to track whether a target date can be met or how the work is progressing.