the site that i wish to be monitoring is a dynamic site. It may have details that are subject to random change. E.g consider the seat status in a train or bus. or even consider the appointment list of a doctor. Now on the site the list will be in the form of an excel table. Having fields, Patient ID, Appointment type, Appointment date, appointment time.

Now suppose that a patient wants an appointment. so instead of putting him at the end of the queue, we can check the appointment list for any random cancellations, at put the patient in that slot.(this is just an example, as obviously the next patient in the queue shoukd be advanced). But considering how people have divded their own time in slots. the free time of the patient shuld match that of the vacancy in the appointment list.