CNN ran an article this morning covering yesterday's Ching Ming festival, and sure enough that's what I attended yesterday with my family of friends. Theirs is a Chinese-Thai family, both parents were born in Hong Kong. They told me yesterday that it was the "Ching Meng" festival, but I didn't put it all together at the time. I was probably thinking about the lunch that was to follow, which was superb.
Bangkok, incidentally, was a Chinese trading settlement in its early incarnation, and there's still a big Chinese cultural component. This area of the city has a large Chinese-Thai population, so this temple has lots and lots of those little "bone condos." They burn the body upon death and remove and preserve the bones afterwards, the ashes they're not concerned with. It gives the parents a chance to be demanding long beyond the period of their natural lives.