Multiple values from Select

This might be a silly question but I just can’t seem to wrap my head around it.

I have a select (dropdown) which uses the trips table with trip names being the text and trip_id being the value. After a trip is selected I need to pass the trip_start value from the trips table to my fullCalendar instance. I need the trip_id for various things so can’t use the trip_start as the value. Can anyone point me in the right direction?

Thanks,
Heather