How do I configure a user so they can change the system time?

A. The ability to change the time on an NT system is a Right that has to be granted through the User Rights Policy in User Manager.

Also see Q. Can I synchronize the time of a NT Workstation with a NT Server?

You can also use a script which automates the granting of the right to alldomain users:

Create the Addtime.bat and Addtime2.BAT files listed below.

Run Addtime.bat with administrator privileges from a computer running Windows NT. This batch file creates a list of member servers using the Windows NT Resource Kit utility Netdom.exe. The output of NETDOM gets redirected to a file, which in turn, gets parsed using the FOR command (part of Windows NT command extensions). The Addtime2.bat file gets called for each instance of \ServerName within the Netdom.txt file. The Addtime2.bat file then issues the Windows NT Resource Kit utility Ntrights.exe to add DomainDomain Users global group to each of the member servers Change the system time user right. The output of NTRIGHTS gets written to a file called Log.txt.

Filename: Addtime.bat 

echo off
cls
echo Creating a list of member servers.
echo.
netdom member > netdom.txt
echo Adding "Change System Time" right to Member Servers...
echo.
if exist log.txt del log.txt
for /F "skip=6 tokens=4" %%a in (netdom.txt) do 
   call ADDTIME2.bat %%a
echo.
echo ----------------------------------------------
echo - Done! Check LOG.TXT for status information.-
echo ---------------------------------------------- 

Filename: ADDTIME2.BAT 

echo Adding right to %1...
ntrights -u "domain users" -m %1 +r SeSystemTimePrivilege >> log.txt