Oh my goodness it worked!! I had to use this page’s advice to make a list from the start input - end input, and I got it!
I should note: to make it work properly, the api workflow pulls the startdate input and changes the hours, minutes, and seconds to 0. Then the verticallist’s data source searches for eventoccurences containing the current date/time, changing hours, minutes, and seconds to 0 to match (otherwise I think the time of day the event is created would throw that off)
Anyway, thank you both for the quick and helpful responses!!!