Referencing cell on different slide in keynote

I am attempting to create Bullet Journal printables in Keynote, to be exported as PDF documents. I'd like to be able to populate the individual dates needed on each slide by referencing a "hidden" slide. So starting 1 Jan of specified year to 31 Dec etc. (Yes, it's a long document).

I can get it to reference a certain cell, that's not a problem. What I'm wanting to do now is for each slide duplicated, or added, for it to continue down the list. In other words, either increase by one in the formula, or reference the next cell down on the list it's referencing.

Formula currently on the first slide is

SUM(Slide 1::Table 1::$A1)

It's currently preserving the column, as the list is only in one column.

On subsequent slides, I've tried:

SUM(Slide 1::Table 1::$A1)+1

SUM(Slide 1::Table 1::$A1)+2

Also

SUM(Slide 1::Table 1::$A2)

SUM(Slide 1::Table 1::$A3)

(manually changing of course)

Which works, but it still means manually changing each slide. Other than manually changing each slide (I might as well copy and paste the dates if I have to do that), is there a way the formula can reference the next cell? Or say, the previous slide's formula plus one?

Hope this makes sense as to what I'm trying to achieve?