YEAR 4
I'm nearly a monoculturist, so Keg time every 6-1/2 days is my big payoff. I am pretty happy when it's over 1 million per change. I think in my oldest savefile (Summer Year 4) at the moment, it's around 1.2 million per change. I'm not sure whether you'd look at that as one big day or a week.
More mathematically, I have 12 N-S/vertical rows (columns) of 44 kegs outdoors on my farm where the Greenhouse used to be. If it's all Ancient Fruit @2310 (Artisan) each (no Starfruit; sad), that's 1.2 million. It's always nice when there is some Starfruit in there.
YEAR 1
I am very delighted in the middle of Summer Year 1 when my Pale Ale Kegs start harvesting every 1-1/2 days. At that point I usually have about 40-60 Kegs, so at 300 per Keg I get 12k to 18k gold every 1-1/2 days. A week or two after that when I hit Artisan profession and have a few more kegs, I feel positively flush with wealth at 20k to 30 k every 1-1/2 days. To do that, I have to chop Wood like mad from day 1, get 8+ Oaks tapped by Spring 12, and plant plenty of Hops on Summer 1, Q. Sprinklers or no Q. Sprinklers.