On Fri, February 17, 2012 4:04 am, Chris Roper wrote:
> Thanks Alan,
>
> I had found that after posting and am busy digesting it.
> I think I see now how they convert to UNIX Time and handle the Leap Year,
> now I need to try and work it back words,  add in the BCD conversions and
> take out the DST portion (we work only with UST/GMT for time stamps).
>
> I also note my error in the Epoch being 1979 I see now it is 1970 did I
> confuse it with the GPS Time?
> With all the software based clocks I have written over the years, always
> in
> BCD, this is the first time I have tried to interact with networks. I
> didn't realise there were so many conflicting time formats out there.

Not quite conflicting- just different definitions- which has resulted in
the recent discussions to eliminate the leap-second:

http://www.bbc.co.uk/news/science-environment-16597191

Clocks have been made way more accurate than the rotation of the Earth, so
they need to be periodically adjusted. I don't think we can predict the
needs for the leap-seconds more than a year or so in advance, so if you
want to keep accurate time-of-day, using POSIX time requires a look-up
table, and may not be accurate with data more than a year or two old.

If you're looking for relative time, POSIX or NTP time works great,
however, if you're looking for time-of-day, GPS time can be more useful.

Matt

Matt Bennett
Just outside of Austin, TX
30.51,-97.91

The views I express are my own, not that of my employer, a large
multinational corporation that you are familiar with.
--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.