You’d check your bank account if money kept disappearing. Check your hours the same way.

Nobody would tolerate unexplained withdrawals from an account, yet most people carry only a vague theory about where their days go. Time is harder to audit because there is no statement, so the losses stay invisible and the story stays comfortable. The remedy is the one you would apply to money: look at the record rather than the impression.

Write down where the hours went for a few days without trying to improve anything yet. Then find the single largest gap between what you thought and what happened. Change that one, and leave the rest alone for now.