I am looking for a way to optimally group people in threes, based on the last time they met.

Example, I am part of a group of 30 people that meets monthly. Each month, I am grouped with two others to meet outside of the group for lunch/breakfast, whatever. I want to let Excel (might need macro?) group me with the two that I have met with the LONGEST AGO. But it needs to be the same with all three relationships. By "the same" I mean optimized (or maximized) for all three of us.

So each month, all the data of who met is entered, and out comes the grouping (which becomes part of the data for the following month, etc.)

I hope I am explaining this sufficiently. When I do Google searches for models, I am getting all kinds of stuff that doesn't apply.

Thanks!