Neowin picked up the news via a Chinese retailer:
According to a tweet posted earlier, in what is claimed to be an internal memo from a Chinese retail vendor, it shows that the Windows 10 April Update will start rolling out on May 9, which falls on a Wednesday in mainland China. It's important to note that due to the time difference, it'll still be Tuesday May 8 in the United States, so the rollout could start then, while it will be May 9 in China.There's no official confirmation yet, but May 8 seems like a logical date. The whole naming is messed up though, Microsoft will be releasing a build version 1803, called April Update, in May!