Temporal comparison formulas to determine acceptability of signature

Hypothetical situation; an employer must sign a document either prior to the end of a fiscal year or prior to the commencement of the fiscal year. The document's signature must occur prior to the end of the fiscal year for which it stands effective, or prior to the beginning of the fiscal year in which it turns effective. So, an employer, for the fiscal year flowing from 10/1/2014 to 9/30/2015, would have to sign a document effective 10/1/2014 on 9/30/2015 or earlier.

Can anyone think of an excel function to accommodate such a situation? I contemplate setting up a formula to determine the latest date on which one could sign a document based on its effective date.

I had assessed a possibility using the AND function. It could identify situations where:

the signature date of the amendment occurred in the same year but in a month after the end of the plan year in which the effective date occurs

the signature of the amendment occurred in a year after the effective date occurs

I thought that I might as well update this thread. I used the DATE function with the YEAR, MONTH and DAY to produce a result of the fiscal year beginning with one year added. I present an upload of such a file.