It’s possible to add a JS filter to set the arguments for the jQuery Timepicker instantiation.
Something like the following although I wasn’t able to actually get it working.
(function($) {
acf.add_filter('date_time_picker_args', function( args, $field ){
args.units = ['hour', 'minute'];
return args;
});
})(jQuery);
It’s documented here – https://www.advancedcustomfields.com/resources/adding-custom-javascript-fields/ – but this contradicts the ACF JS API docs which says to use .addFilter
– https://www.advancedcustomfields.com/resources/javascript-api/.