Microsoft this week released the first preview of what will become Windows 10 version 1809, this year's second feature upgrade and the one slated to ship this fall.
But the debut of what Microsoft calls the "Skip Ahead" build for Windows 10 1809 also hints that the release of the spring feature upgrade, aka 1803, will take place in early April.
On Wednesday, Microsoft forked the 1803 preview of Windows 10 - as it's done before when it nears release of a feature upgrade - so that developers could continue to deliver beta code for that build while also beginning to work on the next-in-line, 1809. (Microsoft uses a yymm labeling system to mark its Windows 10 feature upgrades; 1803 indicates a March 2018 release, while 1809 marks a September release.)
When it forks its preview code this way, Microsoft provides the further-in-the-future build, in this case, 1809, to Windows Insider participants who earlier volunteered for Skip Ahead.
As the current feature upgrade gets close to release, Microsoft switches Skip Ahead users to the following upgrade, so that it can collect feedback on that version even as they continue to polish the one set to launch soon. The bulk of Insiders remain on the latter code.
The point at which Microsoft begins handing out different code to Skip Aheaders comes when the company is close to wrapping up the impending feature upgrade. Think of the Skip Ahead debut as a warning bell, like the one rung at track meets when racers reach the final lap.
Last year, as Windows 10 1709 (aka "Fall Creators Update") neared completion, Microsoft first forked the preview code and distributed a different build to Skip Aheaders on 31 August. Windows 10 1709 began its release cycle on 17 October, or 47 days later.
To estimate the release date for Windows 10 1803, Computerworld added 47 days to 14 February - the day Microsoft forked the code and again gave Skip Aheaders a different build - to arrive at Monday 2 April.
Because the last two feature upgrades launched on Tuesdays - 11 April 2017 for version 1703, 17 October 2017 for 1709 - 3 April, a Tuesday, would be more likely.
Computerworld's alternate forecast would be 10 April, also a Tuesday, because it would better match the previous upgrades' dates, which were closer to mid-month than the month's start.
Microsoft has yet to announce a release date for Windows 10 1803, or give it a descriptive name, as it has those in the past.
The former should be revealed soon if Microsoft follows past practice. Last year, Microsoft's Terry Myerson, the company's top Windows executive, told customers on 1 September that 1709 would launch 17 October, giving them a 46-day notice.
However, notice was even shorter earlier in 2017, when Microsoft waited until 29 March to tell customers that version 1703 would begin shipping 11 April, or just 13 days hence.