Once you have the hour or day set aside, pray that the Lord protect that time from distractions. Tell Him your intention for that time, and then make your schedule revolve around it. Be ready for Our Lord to allow some sort of interference – leave it in His hands. As holy Job said, “If we accept good things from the Lord, should we not accept evil?”
Typically, with those whom Our Lord is trying to coddle, whose feet are wet and whose steps are weak, there is more protection, so that they take the initial step. For those who are more seasoned in the Faith, Our Lord permits more challenges. So, peacefully depend on Divine Providence regarding the timing of your retreat.