User blog comment:Dragonjet/Registration Lottery 2015/@comment-180.190.161.206-20150520151416/@comment-749631-20150520152739

there are no default time, but usually they will update their twitter everyday around 9-11 am japan time, and also the most likely time when they specific further detail about lotteries. Also, as there are little point to start and lottery immediately after the time is announced, so if the exact time were not mention until the predefined date come, then it is most likely for the lottery start somewhere between 3-7pm japan time.