Thanks Amalia! I had the Google Cal and the mini one the template side by side.
The first calendar week of a month in the mini calendar, I adjust manually. From the second row, in each cell, I refer to the "previous" cell+1, and copy-paste or pull this to the end of the row, and downwards.
You'll have to check if it copies the "correct" previous cell, otherwise adjust it. (When on a cell, hit enter, and you can see which cell it refers to).
Does this make sense? If you want, I could make a screencast over the weekend to show how you'd update?