How to format API date/time format on page

For “date that i get from the backednd” that date comes from the “object” (or data set) “eventstart” and the date changes daily. It’s a list of upcoming events. So it is not one specific day… but rather a date that is pulled from the source.

what would that be called? it is data.eventstart? would it be the text box? would it be the ‘eventstart’ from ‘eventstart = data.eventstart’