Hi there Stuart,
Thanks for getting in touch with us on this! I can help you here 🙂
Basically there’s no easy way of doing this, and the support we can provide for custom development is fairly low. That said I can point you in the right direction here 🙂
First of all you’ll need to add a custom field (it can be a default WordPress custom field, a PRO additional field or any other type of field) to store the information. Once that’s done you’ll need to show the extra information alongside the default one. To show the schedule of an event (in various place if not all) the calendar relies on this function: tribe_events_event_schedule_details. Hopefully the output of the function is filterable via ‘tribe_events_event_schedule_details_inner’ (and ‘tribe_events_event_schedule_details’ as well), this basically gives you the possibility of altering the function output.
Please let me know if this helps,
Best,
Nico