WHS2011 is easily set to be an NTP server with a simple registry setting. No need for other software. Here ya go:
1. In WHS's registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NTPServer set the Enabled item to 1
2. Add to WHS an Inbound Rule to Windows Firewall for the port 123, protocol UDP
3. Set all clients to point to the WHS2011 IP address.
That's all, though you may need to log-off-and-on and/or restart the W32Tm service or WHS2011 itself first.
I did also set my SpecialPollInterval to an hour instead of a week, on all machines. The WHS2011 is on all the time so it's time is always perfect, and it's reachable by my clients at all times as well.
You will also need to find a reliable external source for your WHS machine to point to of course. I found one physically-and-web-wise nearby to my location that works perfectly 24/7. Sorry I don't have a link to the list of NTP servers handy just now.