main and child events import

Hi,
how does EventBooking define that the first date of a multi-day exhibition is considered the main event, while all other dates are treated as child events?
Which field or combination of fields establishes this parent/child structure in the import file?Any insight on how EventBooking handles this would be greatly appreciated.

Thx and regards

It is controlled by parent_id field.

- For parent event, parent_id = 0. Also, event_type = 1
- For children events, parent_id = ID of the parent event. And event_type = 2

Regards,

Tuan