I've been tracking tracking my work down to the minute for the past seven years. (timer and log book.)

I started out trying to get to five "hands on keyboard" coding hours a day, five days a week, and realized that it was unrealistic after the first few years.

Four hours of coding time, five days a week works for me. If I'm a little under I work Saturdays, if I'm a little over I take off early on Friday. Unless I'm sick I put in 20 hours of coding a week. You would not believe how nice this way of working is.

Wrote a post on my blog on how to be productive.

Create a Todo list of manageable tasks you can complete in a day. Nothing too daunting mentally or physically.

https://www.rxjourney.net/how-to-be-more-productive