NL does not have the ability to shutdown itself or others ... but ...
Here's what I do.
1. A Windows XP PC wakes up using BIOS RTC every morning at 7am.
2. At 7:06 (plenty of time for WinXP to start) the XP PC uses Windows Task Scheduler to a wake the NASLite server using a WOL program.
3. At 7:08 the XP PC wakes an internet server (also using Task Scheduler). (In your situation you can skip this step.)
4. My internet server (Linux based) runs a task every ten minutes after one hour of uptime to see if certain local IP addresses (other PCs) respond to "ping". If none, it's time to "go to bed"; first shutdown NL using the "poweroff" login, then shutdown itself. (The first PC that wakes up in the morning is either manually shutdown before 11pm or shuts itself down at 11:03pm using Task Scheduler. Other PC may still be running, but if not, then the internet server "puts the rest of the team to sleep".
Step 4. may be too much for your situation (no internet server (mine does firewall, mail, filtering, etc)). In your simpler situation your Windows PC can shutdown the NL, then shutdown itself (again using Windows Task Scheduler).
Search this forum for "automated shutdown" or "scheduler shutdown" ...
Hope this helps,

Georg