This same situation happens year after year. And it's not just TG. Of the several Asia-based airlines that I deal with regularly, including SQ, they're all the same. Some of them are even worse and don't release prices until only a few weeks before April 1. Perhaps European or American based airlines operate differently, so if you don't mind using one of them and they'll offer you a discounted ticket, then that's what you'll need to do. Myself, I find it maddening sometimes, and politely tell TG every year that they're losing business by not releasing their discounted tickets earlier, but I know it never does any good. The same thing happens for tickets after November 1.