jameswilson
ntp is supported in sme server
Read the manual for server manager configuration details
Honestly you don't even have to read the manual, just select the Time & Date panel and configure it.
Usually the local workstatiosn are set from the servers time, when they log in, see the standard netlogon.bat file for the commands to do this.
As far a getting other external machines to use your (remote) server, that seems like a long winded way of doing it. If you have other sme servers elsewhere just configure them to use ntp also.
There is no maintenance needed, it keeps itself synchronised.
Otherwise configure your Windows workstations to directly update from a public time server, see Windows docs/config re which time server to use.
It's a standard setting in Windows.