Count how many n rows are populated

Question

I have a Google Sheet with a lot of data in, and I am wanting to count the number of cells in a column that are not empty, for every N rows.

The column structure has column 1 with the day of the week, the rest are data. I am wanting to say, count the number of occurrences of data I have for Monday, for Tuesday, and so on.

I have managed to find a formula to calculate the total for the same situation as above:

=sumif(ArrayFormula(mod((row(Sheet!BSTART:B)-row(Sheet!BSTART)+1),7)),0,Sheet!BSTART:B)

and was hoping something similar could be done for counting?

I did see that countif is a possibility, but I haven't been able to get it working.

Spreadsheet structure:

Date	Data 1
Mon	data
Tues	data
...	...
Mon	data
Tues	data
...	...

Answer 1

If the example table is in A1:Bx of a sheet, you ought to be able to use the following formula anywhere to the right to get the row count per day:

=query(A1:B,"select A,count(A) where B is not null group by A",1)

You may need to adapt depending on the number of 'Data' columns and whether empty rows within them coincide or not.