The name Windows 10 20H1 means Microsoft expects to release the next major version of Windows 10 sometime in the 1st Half of 2020. This is a rather imprecise date range, and now the latest Insider Build of Windows 10 20H1 has revealed a more precise target date for when Microsoft expects to release the OS update.
Windows 10 May 2020 Update pic.twitter.com/0pWIaFIhn6
— Tero Alhonen (@teroalhonen) September 11, 2019
Discovered by Tero Alhonen, it appears Microsoft has renamed the update to the Windows 10 May 2020 update. As part of the cleanup Microsoft also retrospectively renamed the April 2019 Update, which was released in May, to the May 2019 Update.
So far the May 2020 Update Insider Builds have included updates to Cortana, more worked to make Windows 10 passwordless, more language support options and included the movement of many standard apps such as Notepad to the Microsoft Store.
Like the April 2019 Update, the name only suggests an intended release date, and it remains to be seen if Microsoft will make the target.