Need to calculating working time and days using 2 tables named "projects"+table"attendee"


Hello all,
I have the following setup and problem to solve.
I have a "projects " table and a “attendee” table.

In the projects table I a have linked record field linked to attendees table.
Now for each project I can assign all attendees, working on it.
All attendees working on that specific single project (one record representing one specific project) are gathered in that one linked Field.

Each attendee works different days and working times.
I need to calculate each attendees personal days/ working hours for the the specific project, he/she was working on.

Preferably in that project table. (Not a Must)

I do not get even a close to a solution ( new table necessary?)

Glad for any hints