[time-nuts] On Setting Precision Clock

David Forbes dforbes at dakotacom.net
Sat Jul 22 12:42:16 EDT 2006


At 7:18 PM -0700 7/21/06, Brooke Clarke wrote:
>Hi David:
>
>Yes, I like it.
>
>Should Increment and Decrement work on the whole counter?  for example
>when changing minutes you can only increment or decrement the minutes
>digit and the 10 minute digit follows?
>
>Thanks & Have Fun,
>
>Brooke

Brooke,

I find that the most annoying thing in the world* is a clock that 
requires you to cycle through 59 of the wrong minutes to get to the 
minute you want. So I designed my clocks to use one digit at a time 
setting on the minutes and seconds, but to cycle through all 12 hours 
in one go. For 24 hour mode, you might like having one digit set at a 
timem.

Ideally, you'd set the timezone and let GPS set the clock via NMEA 
strings. Timezone can be difficult to calculate given the lat/long 
info - having the user set it as a number of hourse like -7 or +6 
relative to The Center Of The Known Universe (Greenwich) is easier.

Since DST is also quite difficult to calculate, many in the world of 
exotic electronic clock makers just provide a DST on/off flag for you 
to set manually twice a year. I don't have DST here in Arizona, so I 
don't think about it much.

* Recently I encountered a clock that was even more annoying. It was 
a Seventies digital clock of the mechanical wheel type on an electric 
cooking range. The timesetting knob was key-shaped so you could only 
turn it a half-turn at a time, which incremented the clock by all of 
three minutes. Think how many turns it took to move it 6 hours!

-- 

--David Forbes, Tucson, AZ
http://www.cathodecorner.com/



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