I don't like to let anything sit longer than about 2 weeks on fruit so even if the fermentation has been a little sluggish, I'll pull the fruit bag out and rack into secondary... but so far almost everything has been close enough to finished for me (SG below 1.010) by two weeks, except the show meads, they were only around 1/3 sugar break at two weeks but not violently fermenting so I racked... so if you're starting out with a traditional mead with the intention of fruiting it in secondary, it may well take longer to finish than fermenting fruit in primary with the honey.