The SQ lounge is pretty much the best *A lounge in BKK, BR is a close second, the TG ones and the contract lounges are rather meh. The SQ lounge is open from 6:30am to 11pm and will fit the AI flight timings. They take their hours rather seriously and stop service aroun 10.15pm. At 10.30 they start reminding you that they are about to close