Proper Time

Proper Time

When I was building and installing telescopes, a critical element of the RedHat installation was assuring that the system time was properly set and maintained. That system time was the basis for many of the important astronomical calculations for the telescopes. There are, however, many other programs and processes in Linux that rely heavily on the system time. Setting and maintaining the time in a Linux system is quite easy, thanks to the ongoing refinements of the OS.

Linux relies, for the most part, on a software-based clock. The hardware clock maintains the time while the system is down, passing its responsibilities to this software clock at boot time. You can, however, adjust both the software and hardware clock via tools available in most current distributions. Dateconfig is the most recent of these tools, replacing timeconfig as the time adjustment tool of choice in Linux.

From a console window, you’ll need root access to use the dateconfig tool. Enter the command dateconfig at the command prompt as a normal user and you’ll see a gui password prompt for the root user.

Dateconfig allows you to set the current time and date in a tabbed gui interface. The first tab contains the date and time information for your location. The second tab allows you to select your time zone and whether or not the system clock should use GMT as its base. This is the standard for Unix-based machines, but it’s not a requirement for your system.

The most useful element of the dateconfig tool is it’s ability to set up automatic time adjustment for your system via the Network Time Protocol (NTP). NTP servers exist solely for this purpose - to feed millisecond accurate time to network-connected computers around the world. The NTP HowTo is a useful tool for understanding how this protocol works and for instructions on implementing it in your Linux system. The dateconfig tool offers the option to adjust your system time automatically from the date and time tab. By making these automatic adjustments, you’ll never have to worry about the integrity of the system time on your Linux system.