I thought it may be beyond even the greatest minds on this site…..even yours, but thank you so much for replying, really appreciate it, usually these question stay in the ether.

This is my first request and I hope you can help as I have searched everywhere for a script to do this.
I have an Indesign document that is a complicated calendar template
the months are all tables :1 x ROW with either 28,29,30,31 cols.
However, the grid which these above contain many rows (12) and col(37)
If I try any of the selection scripts then these change all the tables in the entire document including the base grid.
So I need to be specific about selection!

I need to select and change the column spacing for the first and last cell for each of the 4 date single rows (28,29,30,31 cols)

Is it possible to select say, tables with 1 row and 28 cols and reassign a col width for the first and last cell?

There are 12 x 7 (84) single rows to change, so a script would be brilliant for this.

Any help would be much appreciated
(BTW I know how to copy/paste/position scripts in Indesign….have performed this at least 30 times today!)
Indesign CC2015 on a Mac