I actually did this last year and the year before when I wrote two books (not to final draft) of a trilogy. I kept a daily and cumulative log of word count and other things.
The first draft of the first book came to 504,967 words, which I wrote from 12 May, 2013 to 23 September, 2013 (135 days). The average daily word count was 3,740. The lowest daily word count was 1,373 on 13 May. The highest daily word count was 9,336 on 1 June. From 12 June onwards, I didn't dip below 1,800 words per day.
Along the way I also created several glossaries/appendices with characters, places, etc.
After completing the first draft, I did a second draft (mostly proof-reading, little content change other than to get consistency across details). That took from 24 September until 11 November, though the bulk of the work was done in the first few weeks (after which point, I became increasingly burnt out, but more on that below).
I then spent the remainder of the year thinking about the next book and preparing an outline for it. Then the real mania began.
From 1 January, 2014 to 5 March, 2014 (64 days), I wrote 433,765 words (daily average: 6,778 words). The lowest daily word count was 2,388 on 8 February (more on that day below). The highest daily word count was 11,932 (29 January), though there were also two other days >11,000 words, and one >10,000 words.
Today is the first day since then that I have looked at the entire project, though it has increasingly been on my mind for the past few months and I am finally regaining enthusiasm for it.
Before I go into the whole psychology of it, I'll just give some background on the entire process of beginning writing. The ideas for the first book had been floating around in my head for at least a year (maybe two) before I started writing it. At the time, I had two friends who were writing novels. One had actually moved interstate to isolate himself in a small town so that he would write. After a year, he had about 250,000-300,000 words. After he moved back to Melbourne, I later asked him how much he wrote per day. He said that he usually struggled to get a couple of paragraphs per day done, which actually shocked me. He is going about it the complete wrong way and he is never going to get his book finished. It is largely for this reason that I haven't told him that I have written anything. He is kind of a fragile guy and I think it would knock the wind out of his sails completely.
My other friend is the guy who runs the
Millennial Woes Youtube Channel. At the time, he was working on the nth draft of his novel. Since then, he has been focusing on other things (a novella based upon something from within the novel, various graphic programmes, and of course, his Youtube channel, for which he uploaded over 400 videos last year, plus a whole lot he has yet to upload). Before I began writing, I read his novel and I spoke with him at length about the writing process. He showed me logs, including of edits, etc. and gave me lots of suggestions. I was really inspired, and still am, by his work ethic with the whole thing. He also gave me the helpful advice of printing a draft out, if possible, which I could whilst working at a school. Now, with the books running to something like 800-1,000 pages, that would be quite time consuming and expensive. Regardless, reading and editing in hard form was better, I think. It was a bit like the difference between reading a book and an e-reader. I then made changes on the computer.
Before I actually came to start writing, I wrote a fairly detailed set of plans for the first book. The plot and the purpose of the book changed throughout the planning and the writing, but it really helped to plan it out. I wrote a series of timelines and other things to keep track of what was going on (because there are four main characters, whose lives converge and diverge at different points over a 38 year period). I also wrote loose outlines of the plot, which I fleshed out a bit into sections, and then chapters. I can't remember exactly how long that process took for the first book, but it was only a few weeks because many of the ideas had already been in my head for at least a year, some much longer.
The other thing I did was that at the end of each day, I wrote a plan for what I was going to write the next day, so that I could hit the ground running. In that way, I was able to achieve flow and average ~1,500 words per hour when writing.
I did all of those things for the second book also, but the process seemed much more rushed because the ideas were forced in less than two months, rather than percolating up in a more organic fashion as for the first book.
There was no point at which I really got writer's block and didn't have anything to say. The first book involved more access to the internet (which I managed to be fairly disciplined about, mostly using it for researching minor details). The second was largely conducted whilst on vacation, part of which was in Australia at my parents' holiday house in the countryside with no internet access.
The first book I really enjoyed writing, though the sheer workload of it was still tiring and I was burnt out a little towards the end, but especially with the editing. The second book was something else entirely. I definitely got in a zone and a work ethic when writing. I was obsessed with not writing fewer than 2,000 words per day, to the point where those 2,388 words on 8 February, and the 5,139 words the day before were written on the return trip from Australia. If I remember correctly, about half of the 5,139 words were written between flights at Changi Airport in Singapore, and the 2,388 words were written about 22-24 hours into the journey, on the train trip south from Taipei. I remember feeling distinctly battered by the end of it, but I had the words down, regardless of their quality. That's how I felt about the entire second book, and I was extremely displeased with it, feeling that I'd got a lot of words down, but not much of worth. Those feelings are largely what have stopped me from looking at the project since, so I would offer a strong warning about pushing too hard. I understand the desire to just get words on a page, and I think that it's probably better to err towards just getting garbage on a page than fretting over writing the perfect sentence or paragraph. The work can be edited or refined later, but burnout is a real thing.
As to how I had time to do all of this, I made it the focus of my life. I usually wrote for an hour or more before I went to work (I lived nearby), so I usually already had a good 1,200+ words under my belt before the day had begun. My job was pretty slack (only teaching about three hours per day, with several blocks of a couple of hours of free time per day), so often, I got all my writing done by the time I went home. I usually only wrote in the evenings if I had a long chapter that I was in the middle of and wanted to finish. Aside from anything else, it was actually really good to write at school because I hated my job, so it served to keep me from dwelling on that. On weekends, I usually wrote for a good four to six hours, before doing something else in the afternoons and evenings. For the second book, a fair part of it was written on vacation, as I mentioned above. Sometimes, I went on tears for the entire day. Sometimes, I wrote at other times. I actually had to isolate myself a bit from other people so that they wouldn't distract me.
As I also wrote above, I'm getting back into the idea of writing again. My parents are going to visit me soon, so I probably won't do too much until after they leave, but I have a lot more things on my plate right now, so I might just have to bite subsequent drafts off piecemeal, rather than thinking I can just go on a bender for a couple of months. It might be better for my sanity, also.