Upcoming date entry - recent date

Hi.  This is my query:

We have a custom entity, IP Titles (Intellectual Property Titles). Each title (entry) has 10 - 30 due dates for filing for the lifetime of the title.  I want a seperate field, called "Upcoming Due Date" that takes the recent upcoming due date of the 0-30 fields that have data.

Is there a way to do this without code? We have some javascript code running on other entities - and in these cases the business rules don't work where javascript exists.  Since I have working business rules in the IP Titles entity, I'd rather do this without code.

Please advise.  Our working process is that our IP Manager files out the due dates of the Title's lifetime in advance,and would like a seperate field that simply let's her know the upcoming date for that title.

THank you,.