How long do you spend writing in a day?

Sometimes every minute of it, till the early hours. But it depends how far into a book I am. It’s hard to motivate myself at the start of a new one. I spend a lot of time staring out the window, doing gardening and reading too, anything to put off the job in hand. But once I’ve got going I gradually waste less time and don’t want to stop writing for anything or anyone.