[time-nuts] Happy Leap Hour Day !

[Tom Van Baak]

> Tom, I was under the same impression as you, regarding RC clocks. However, I 
> just pulled/replace the battery on one of mine and then forced an update. It 
> still is an hour off. Am I missing something, or is the clock?

What make/model? This is interesting. I have seen
something like this before. It might work tomorrow. It
might take one 2 AM transition. Or it might work in
another hour when 11-Mar-2007 UTC is over. Can
you try it again a few times and tell me when it first
comes up with the correct time?

If so, it's another untested bug in RC clock firmware.

Read the WWVB docs and note the two DST bits (57
and 58) are quite tricky on the day of the switchover,
especially considering the difference between the UTC
day and the local day, when the reception is made vs.
when the clock needs to (or needed to) be advanced.

See also:

WWVB Radio Controlled Clocks: Recommended
Practices for Manufacturers and Consumers 
http://tf.nist.gov/general/pdf/1976.pdf

NIST Special Publication 432
http://tf.nist.gov/general/pdf/1383.pdf

/tvb