The MIN function can be used on any fields supporting aggregation which have a numeric type:
It will return the minimum value across all the values in the query (or the set of values being evaluated for the current Facet or Group).
The MIN function, like the AVG, MAX and SUM functions, takes a single argument, which is the name of the field it should calculate over.
This would return the date/time when the first entity of type script was created.
Min(CreatedAt) WHERE EntityType = Script