Hidden in Windows 10 Technical Preview 2 is a new clock and calendar you can access by clicking on the clock in the taskbar. Here’s how to enable it.
In the shipping version of Windows 10 Technical Preview 2, this flyout looks like the version from Windows 8.1.
But if you make the following change to the registry (by running regedit.exe) you can view the new version, which I assume will officially debut in a future build.
Navigate to HKLM\Software\Microsoft\Windows\CurrentVersion\ImmersiveShell
Add the DWORD (32-bit) key UseWin32TrayClockExperience
Assign the value 0
There’s no need to reboot. When you click the clock in the taskbar you’ll now see the following.
If you click the “Additional clocks” link, the Alarms app will run and navigate to the World Clock view. You can add new clocks here, of course. But they will not appear in the flyout.