How well do you know your own schedule? Not just the events on your calendar but your actual, verified routine? When did you last record those events as they happened, repeated over time?
Consider a time audit: For a day, make a record of every noteworthy activity in which you participate and when it takes place. You might have, for example:
And so forth. See how granular is practical and how long you can sustain the habit. The more data, the better. Finally, review it.
The results of your time audit may surprise you. Did you realize exactly how much time you spent on YouTube? On reading books? On email? Take a hard look at the numbers. Find the patterns. Now that you have data, how will you change your schedule going forward?