Research on deep work keeps landing on the same number: around four hours of genuinely focused effort is what most people can manage in a day. The rest is meetings, messages and recovery. Accepting this changes how you plan.
Protect two blocks
Split the four hours into two blocks of two, ideally one in the morning and one after lunch. Put them in your calendar as meetings with yourself, and defend them like you would a meeting with your manager.
Decide the night before
Write down the single most important task for each block before you finish work. In the morning, there is nothing to decide, only something to start.
Batch the shallow work
Email, messages and admin go into the gaps between blocks. Check them on purpose, two or three times a day, rather than whenever something pings.
End on time
The four-hour day only works if you stop. Finishing at a set time makes the focus blocks feel more precious, and gives you an evening to recover for tomorrow.
