Time in the bucket is not a good guide. I had an elderberry batch that sat 45 hours after I pitched the yeast and did nothing. I was getting ready to pitch another batch of yeast and 3 hours later, at 48 hours after pitching, it started bubbling. That's 2 days of nothing. If I had transferred at 3 days, it would have been way too soon. You can go by the low specific gravity, which would indicate that fermentation should be almost done, as many on here suggest. However, they suggest 1.030, 1.020, 1.010, 1.000, etc, so there are a lot of opinions. You have to make the judgement; A. is the fermentation in the bucket so slow that the CO2 being released might not cover the large surface area of wine in the bucket and protect it from oxidation? and B. is the fermentation so vigorous that it will foam up through the airlock in the carboy if you transfer? There's a pretty wide margin for error as witnessed by the different sg numbers people suggest. Also, when you transfer, you can leave a lot of yeast behind and slow the fermentation even more. But 4, 5, 6, or 7 days might be needed.