Conditional formatting across two records?

[MariaAux]

Hi there,

I have list of classes (6 on Mon, 7 on Tue etc. - 40 records in all) in list view that I would like to print with a thick balck line between the days, not between each class. I was having a think how to do this and the only solution I could come up with was to create a an empty text box and create a conditional formatting in which if the 'Day' field in the current record is different to that of the 'Day' field in the next record, then the empty text box would be conditionally formatted as black fill.

However, I am struggling to create a formula for comparing the data of a recordm in a current field with the data of a record in the next record... Would you please be able to help me? Or even better, do you have any ideas how to do this another way?

Thanks so much in advance and have a fabulous day.

[comment]

Why don't you use a sub-summary part (when sorted by day)?

[MariaAux]

That is exactly what I was looking for. Elegant, easy solution.

Thanks so much and have a fabulous day.