What type of field is date-times?
ACF shortcodes only work with simple text based fields, anything form the “Basic” section of the field types. Most other field types will not work.
Is that the field name?
It should look like something like this [acf field="dates_times"]
not sure why your adding the enclosing {$ }
https://www.advancedcustomfields.com/resources/shortcode/