Identifying data by time and day of week

Hi,

If someone could help with the following query it would be greatly appreciated.

In the attached file you will see data for each half hourly period of a month – the date on the left hand side, and the time period at the top.

You will notice in the file that I have highlighted both the highest and lowest figures in the data (highlighted in orange and blue respectively).

All the data needs to be split into 3 categories:
1. Core (highlighted in green)
2. Unoccupied (highlighted in dark blue)
3. Shoulder (highlighted in grey)

Underneath the data I have created formulas that work out the total data in these time frames.

However, the key aspect I need help with is that weekend days (Saturdays and Sundays) also need to be classed as unoccupied data.

If someone could help it would be greatly appreciated.

Many thanks,

James