I know I’ve used lastUpdatedStartDate and createdStartDate, and always assumed as well that startDate was the event date, but also welcome confirmation here!
Yes I think @chase.freeman and @Matthew_Boddie if the endpoint is an events endpoint then it will count the startData and endDate as eventDate, but I think it is different for other endpoints such as the enrollment endpoint.
BTW, endDate functionality has changed after 2.37 and excludes the date entered. I.e. endDate of 2024-07-22 will now exclude July 22, and bring any/all events prior. [DHIS2-17656] - Jira welcome all votes for this one!