Counting number of days in several periods ignoring repeating dates

Hi there everyone!

There is one issue I cannot solve. Hope to get your help on this.

Basically I have 3 columns:
1) person's name;
2) date of arrival to the country;
3) departure date.

This data is info on employees of a company arriving to the country for the provision of services.

I have such data on several companies. I may need to do 2 things with data on each company depending on the circumstances:

1) I need to check the duration of stay of company's employees in the country in days. However, if 2 or more employees were present at any particular date, this day needs to be counted only once.

2) I need to check whether the duration of the stay of representatives of the company did not exceed 183 days in any consecutive 365-days period (not calendar year).

Thanks in advance.

Cheers.

I understand the task but a sample workbook of how the data is arranged would help. Click Go Advanced down to the right to attach a workbook.