You can see lots of information on the Agent Console, including 'Last Reboot Time'. 

This requires some explanation, as 'Last Reboot Time' correlates with what can be seen on Windows Task Manager, and likewise, it is affected by whether Windows Fast Startup/Fast Boot is enabled or disabled. 

Windows 10’s Fast Startup/Fast Boot works similarly to the hybrid, sleep mode of previous versions of Windows. By saving the operating system state to a hibernation file, it makes your computer boot up faster, saving valuable seconds when you turn your machine on.

Fast Startup is enabled, by default, with Windows installation, on most laptops and some desktops, but it doesn’t always work perfectly, and there are some downsides that may make you want to disable it.

Fast Startup/Fast Boot

How Fast Startup/Fast Boot affects the 'Last Reboot Time'

Shutdown

Scenario 1: Windows Fast Boot is enabled and you shut down the device: The 'Up time' in Windows Task Manager and the 'Last Reboot Time' on Atera will never change.

Scenario 2: Windows Fast Boot is disabled and you shut down the device: The 'Up time' in Windows Task Manager and the 'Last Reboot Time' on Atera will change.

Restart

Scenario 1: Windows Fast Boot is enabled and you restart the device: The 'Up time' in Windows Task Manager and the 'Last Reboot Time' on Atera will change.

Scenario 2: Windows Fast Boot is disabled and you restart the device: The 'Up time' in Windows Task Manager and the 'Last Reboot Time' will change as well. 

Disable Fast Reboot

To get around this, you can disable Fast Boot, and upon device shutdown, the 'Last Reboot Time' will change accordingly.  

Enter this command in the command prompt or run it as a script.

REG ADD HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Power /v HiberbootEnabled /t REG_DWORD /d 0 /f