[ Thanks to GM for
this link. ]
“In part_1_of_Setting_the_Clock_in_Linux we saw how one could
change the time or set the time and date on their computer. This is
important because if the time were to get out of whack we need to
fix it. But one thing we didn’t talk about was “How do we know
where to find the correct time?”. In this article, I will attempt
to address that issue using what I have learned over the last few
weeks. In Part 1 we also saw how the system and hardware
clocks interact to keep track of the time….”
“This method is what most of us use. We find a source of
information that we trust and use it to set our system clock
manually. That source could be almost anything. It could be the
wall clock sitting in our room, the time we get by calling a
specific phone number, or maybe there is a television channel that
shows the time (including seconds). In these cases, the we can’t
really expect to have accurate time to the second. What we can
expect is within a few minutes depending upon the source we are
using. For most of us, that is not a problem. But for many of us,
we want a more accurate time measure. Enter the National Institute
of Standards and Technology…”
“In fact, you may already be using a clock sitting in your house
that receives a radio frequency that sets that clock. That is one
of the services provided by the Time and Frequency Division of
NIST. These clocks never need manual setting because they update by
radio waves. So if you have one of these you know you have an
accurate source for the current time and it is just a matter of
transferring that time to your linux system using a simple
command.”
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