Issue: I need to manage the end of series data presentation when the x-axis
dates exceed the current data set, anticipating additional data over time.
The values are calculated and having the formula present before the data is
available returnes a #DIV/0 error.

Current State:
I have a version of spreadsheet that automatically appears to copy down the
formula when data is entered. Otherwise the cells are clear, protection is
off, hidden values is off, there appears to be no macros present.

Question:
How was the spreadsheet set up to accomplish this?
I can send a copy to anyone who want to tackle this question.