Surely writing the first draft of a novel in 100 days is possible. And having a demanding job is no excuse:
Great writers have done it
Yes, you have a job. Yes, you have a family. Neither have stopped great writers in the past. The poet Wallace Stevens was a vice president of an insurance company and an expert on the bond market. The young T.S. Eliot was a banker. William Carlos Williams was a pediatrician. Robert Frost was a poultry farmer. Hart Crane packed candy in his father’s warehouse, and later wrote advertising copy. Stephen Crane was a war correspondent. Marianne Moore worked at the New York Public Library. James Dickey worked for an advertising agency. Archibald MacLeish was Director of the Office of Facts and Figures during World War II.
—found on Peace Corps Writers, written by John Coyne
I’ve been able to do it when on assignment (a first draft in 5-6 weeks), but never-ever for myself. Being a ghostwriter is fun, but also somewhat sad. I need to find a way to write with such mad dedication for myself. After this assignment, I’ll have to remind myself that I said that. I tend to forget.