I was asked when I write and for how long, but there’s no simple answer because time at keyboard has never been my writing metric. So, it can vary quite a bit day-to-day and has varied even more over time.
When I was starting out I wrote mostly in the late afternoons and evenings after my college coursework, from 4-6 hours. While Laura was in grad school I wrote 6-8 hours a day most days while she was at school—basically 10-6.
For the early Blade books I was writing mostly 9-12 in the morning with a second, smaller bite at the apple starting around 2. With the later Blade books and middle grade stuff I’ve often been doing most of my writing 3-5 in afternoon.
Some of the variability is writing speed. When I was starting out I wrote 2-4k words in 6-8 hours, of which maybe 1-2 was ultimately salvageable. Now I typically need to write 1-2k words a day for a deadline and I can use 85-95% of what goes on the page in a session. That can take anywhere from 1-6 hours to write depending on whether I know what happens next or not and if I’m in flow state.
I also used to do most of my thinking about the book while I was at the keyboard and trying to write. These days, that part of the work is quite often a separate step that involves walking and talking to myself. That, and I have a lot more non-writing tasks that are part of my job these days.