Figured this was timely considering the recent time change. Recently I was asked by a fairly young Linux user if he should be concerned about the upcoming 2007 daylight saving
s plans recently implemented by congress. Well, I figured that I was now presented with a golden opportunity to explain Network Time Protocol(NTP).
Well, a bit of historical context would be helpful. UNIX and UNIX-like systems (ie Linux, xBSD) have always been capable of networking. In fact, the respective kernels for each of the aforementioned operating systems have relied upon a robust, open TCP/IP stack for quite awhile. I estimate this has been true for at least fifteen-years or more. The NIST servers
atomic clocks (no BigBen isn't one of them), are readily accessible via public domain IP addresses.
Though, the Redmond wooly mammoth was slow to reliably network its desktop product. It was widely recognized to have a fairly worthless TCP/IP stack. In fact, all of the products prior to WinXP were very poor in this category(probably many others too). I understand XP was vastly improved due to its 'borrowing' of BSD TCP/IP stack. Gotta love those BSD licenses. I digress.
Some might ask the obvious question, "Why can't I simply rely upon the CMOS battery to keep time on my PC ?" Why indeed.. Well, the computer BIOS is dependent upon your PC CMOS battery. Your battery will never retain the same charge as it did during at time of purchase. As with most batteries, it will eventually lose its floating charge. As the battery weakens, your time will begin to drift and eventually be off several minutes throughout the course of the year.. In some severe cases the degradation is significant and your system could be behind a couple hours.
Well, The reality is that all you must do is point your NTP program at the appropriate server
atomic clock. There are thousands of these servers located around the world. These NIST servers clocks _always_ maintain the appropriate time.
Psst. M$ users don't fret, with the advent of XP, you now have access to the same servers
atomic clocks too. They've just hidden it from you. If your machine isn't not connected to the internet, it will rely on your CMOS battery and be wrong.. Nothing worse than incorrectly time stamped email ;)
If you're a Linux user you simply need to run NTP server daemon, and manage it in crontab. If you're running any other recent distro(last 10yrs), it probably is already setup.
It doesn't matter what daylight saving
s schedule is presented NTP will solve the problem transparently.