On Tuesday, September 26, 2017 at 9:52:24 PM UTC+2, Peter Z. wrote:
This really worked, Hutch. Great idea, how to resolve the issue in Google Docs. Thanks.

I would just add the following syntax, so the months can be ordered from left to right ascending in order:
=year(A3)&"-"&if(month(A3)<10;"0";"")&MONTH(A3)
P.