Please be aware that Yogyakarta has multiple airports and that these results are for all airports serving the city.
The best month to fly between Yogyakarta and Banjarmasin is August and the most expensive month to fly is November. (Average prices, based on 1980 datapoints.)
The best day to arrive at Yogyakarta is Sunday and it would be best to avoid Tuesday, as prices are on average 8.6% higher than on Sunday. (Average prices, based on 2054 datapoints.)