That's why calendar-based systems are so inefficient. Have what you need, when you need it. Most interruptions are in your mind. Come on, admit it. If you want the right picture, you need the right lens.
Perspective is like a camera.
Sometimes, you need to use a wide-angle lens to see things more broadly. Other times, it's necessary to zoom in for a close-up view. To really be on top of your commitments, you to be able to see everything, including the big picture, the details, tomorrow's commitments and next month's plans. There will always be more to do than time to do it. Just because something feels urgent, doesn't mean it's important.