Please be aware that Bangkok has multiple airports and that these results are for all airports serving the city.
The best month to fly between Bangkok and Da Nang is January and the most expensive month to fly is October. (Average prices, based on 200 datapoints.)
The best day to arrive at Bangkok is Friday and it would be best to avoid Saturday, as prices are on average 534.44% higher than on Friday. (Average prices, based on 207 datapoints.)