Generate a full detail guide on the concept of scheduling 'buffer time.' The guide should be practical and focused on time management for mental health. It must include sections on: 1. Why Back-to-Back Schedules Create Chronic Stress. 2. How to Intentionally Schedule 15-Minute Buffers Between Meetings or Tasks. 3. What to Do During Buffer Time (e.g., stretch, breathe, look out a window). 4. How this practice can prevent end-of-day exhaustion. Please include a supportive disclaimer.