Time Server App

I have a projector that has a schedule function we want to use to turn it on and off at specific times. The issue is, once it is turned off it does not keep it’s internal time. It relies on NTP to keep it’s clock set. If NTP is not available the clock defaults and the scheduled events will not trigger.
I am finding all kinds of freeware/shareware NTP monitor apps. Is there an NTP server app out there that will allow me to use the PC that is spooling content to the projector as an NTP server?
It is on a standalone network with no connection to the outside world.

Thanks,
Robert