Good question...3 months to write it, then a year and a half to find the time to finish the edit, develop the business and a brand. From what I have learned (I am doing a campaign on my author page to help self publishing authors, if you want to write a book please take a look at that as it may save you dome time!) I am confident I can do my next novel in 3 months. 2 month writing and 1 month editing. The book writing itself is quicker if you have a good idea to start with-sounds obvious I know. I say this because I never struggled with the story, just the editing and presentation.