[geeks] DST change costs

[Doug McLaren]

On Wed, Jan 17, 2007 at 05:30:27PM -0500, Charles Shannon Hendrix wrote:

| > Are you sure about that?  If it receives a signal from Colorado, the  
| > DST info is encoded in that signal with the time.
| 
| I know the DST information is encoded, but I didn't know that included
| the day of the change.

DST information is included in every single minute -- there's a bit
that states if DST is currently in effect or not.

References :

   http://tf.nist.gov/timefreq/stations/wwvb.htm
   http://tf.nist.gov/timefreq/stations/wwvbtimecode.htm

(the second link gives the actual protocol of the WWVB time code.
It's really quite simple.)

Now, it's entirely possible that your clocks ignore this bit entirely
and figure out when the DST changeover happens on their own, but that
sounds a bit silly.

Don't forget that not only your OS needs updating -- in general java
includes it's own timezone information rather than getting it from the
OS, so your JVMs will need updating as well.

Either way, I'll bet the overall costs of this change ARE substantial.

-- 
Doug McLaren, dougmc at frenzied.us
99% of people have more than the average number of legs.