How to count number of people per time interval

Anyone who could help me create a formula that will automatically count the number of people available per interval. I need to see the count in a 30 minute interval. I need to set a schedule for a team who works 24/7. I would also have to consider the break scheds on it. I would really appreciate it if someone can help me on this.

Here's a quick solution. I'm not sure what kind of data you are working with.freevsbusy.xlsx