Proper wine producers make one big batch of the stuff each year, so just label with the year.
I'm making something each month, much of which will have a recommended aging period of at least a year. It suddenly occurred to me that when I've built up a bit of a collection, I'm going to forget when some of it reaches a year old if I only label with the year - I have a spreadsheet I'm using as a brewing diary but it will be inconvenient to search. So I want to label with month (or full date) as well. Question is:
Date I mixed it all up and started the ferment
Date of last racking, when ferment stops and aging begins