I'm a 29 year old freelancer / digital nomad, been traveling and doing high-profile tech contracts for last 5 years. I go with the flow. It really depends on the contract and what's currently going on in my life, or where I am.

Last summer I was in Europe and I've been working 10-12h per day in August (my peak month so far). June-November approx 4-6 hours a day.

Now I'm in Koh Phangan, Thailand and work few hours a month, but fully focusing on healthy lifestyle and training/meditation.

In April I go back to Europe and plan is to grind hard for the next few years. I work in bursts. My routine when I work full-time is having breakfast at my place or a coffee shop and working from there in the morning, hitting the gym around noon, then more work at home/another coffee shop, and unwind during the evening.

There are exceptions to this, if I don't feel productive in the afternoons, I postpone work for evening. I again tend to feel the "flow" of my mental productivity and organize around that. Never had any strict rules and it's been working pretty fine so far.