Rolling sickness tracking at work

Hello everyone,

My level of Excel knowledge is fairly basic. I need to design the most simplistic way to monitor sickness for a small business on a rolling basis. (Total absences in a rolling year, number of periods of absences in a rolling 3 month period, number of separate days in a rolling 3 month period)

Would someone be able to suggest the easiest way to display and track the information as described above?

I appreciate any help as I'm a little stuck with this.

dnlshllrd