I've received several questions recently asking in what time frame secondary essays need to be submitted.
Frankly, this is a hard question to answer because the sooner you can get secondaries in, the better, but if you don't do quality work, you could bomb your candidacy.
The question reminds me of one I get frequently: What MCAT scores should I target? Well, the higher the better, but there are downsides to fixating on a number.
So, while you might have heard the popular belief that you must get your secondary applications submitted within two weeks, that's completely arbitrary. What you want is to do outstanding work as efficiently as possible.