Is this a problem for you? I track seat time, lame as that seems. In education, the issue is always about how much the students have learned, so seat time is a cruel joke.
On the creative side, the issue is about how much is created. The sumo brush and a second? A masterpiece. A writer and a decade? Another.
I just sit down and write every day of the week. Six in the morning. I may not be a great writer, but I am persistent.