Wish I could selfishly suggest that you shoot for one daily, but I know how much work goes in coming out with a truly good story. And so I'd say three days is about perfect. Not too long to lose steam, not too early to be incomplete. :)
Hey, and if you have the bandwidth, please tell me what you think of my latest: https://steemit.com/fiction/@sandzat/the-evil-beauty-short-story-part-1. Thanks! :)