goal for April

By August 15 I want to have a book contract from a publishing company and to have completed a draft of the manuscript. I have four companies I am starting with who want proposals with very similar questions. I can work full time on this project for the next four months (with the exception of a wedding trip and a family vacation and a graduation celebration). I’d like to complete the proposals (which include a sample chapter. I have a good draft of it that needs editing and polishing). I’m thinking of April 15 as the date to have the proposals off to the publishers. And another chapter by end of April. But I’m wondering if that is too ambitious. I can aim for B- but people will be deciding whether to publish based on what I send in. I don’t know what grade is needed to have a proposal accepted. Thoughts?

Another idea is that on April 15 I will evaluate if the material is ready to submit or if it needs more work. I’m having trouble knowing how to plan for April when I don’t really know how long it will take me to get the material ready to submit. How do you go about estimating how long to allow for projects?