How do I change the time

Since DST began in New York, I have many users that have an extra hour added to their clock. I changed the settings to accept DST then I rebooted and to no avail. I removed the selection and got the same response. I changed the CMOS setting to1 hourearlier and it did not help.
We are on a novell LAN and the server has the correct time but EST. What do I do to correct this.