While experiences differ from team to team, my day was similar to this. Every morning I would get myself my breakfast and a coffee, then sit down and browse through my emails. I would reply to any that needed my responses, and read over various emails that were important to the company or my team. Around 10AM morning meetings tend to start. I would sit with my team and talk about our current sprint, the tasks that others were working on, and make updates on my project. Since my project was separate from the general backlog of tasks, my contributions to meetings were not as common as opposed to full time members. I would then meet with my mentor or manager and work until around noon. At noon I would take lunch for an hour and catch up with my fellow interns in the cafeteria, discussing our projects and non-work related topics.
After lunch I would head back to my desk and continue my work. Most of my days were spent researching, writing code, understanding our codebase, and asking my mentor and team for help. The team I was working with had a very large codebase, and used many tools and services I did not have experience with going into my internship. Every day was a learning experience, and seeing how these tools could be used to help our development process. Around 3PM I would take a small break for myself, either by taking a walk or getting a cup of coffee. After my break I would continue my work or attend afternoon meetings until 6PM, where I would fill out my time card and head home for the day.