Create a table with new rows

Dear community,

I have another challenge to overcome.

I have two tables: 

• Payroll table with pay date of each employee
• Project table with start and end date and  % project attribution of each employee

I want to create a new table that includes for each month:

• Start date
• End date
• Employee
• Project
• %Project attribution

This table is created based on start and end date of date's project. For instance, first project begins in 1st January and end in 8th of August, so the table has to have as many rows as months are included between the start and end dates, only for this project. Verify each project and do the same for each month including %project attribution. I attached an image to try to clarify all the details.

The thing is that an employee can be working on several projects in the same month and the idea is calculate the %project attribution for each month and each project, based on project table.

Thanks in advance for your help.

José Luis