Microsoft never sleeps. Even before the Windows 10 May 2019 Update (version 1903) started to roll out, the company began working on upcoming feature updates to Windows 10. As it did with version 1903, Microsoft has been releasing a series of public preview builds to members of Microsoft’s Windows Insider Program.
After years of using “Redstone” in its code names, Microsoft switched to a new format with the May 2019 Update. The new code names use a YYH1/YYH2 format, with the YY standing for the last two numbers of the year and H1 or H2 referring to the first or second half of the year. So Windows 10 version 1903, which was released in May 2019, was code-named “19H1” (for first half of 2019) rather than “Redstone 6.” The next feature update, due in the fall of this year, is code-named “19H2,” and the feature update that’s coming in the spring of 2020 is code-named 20H1.