[LEAPSECS] A leap second proposal to consider -- LSEM
Warner Losh
imp at bsdimp.com
Wed Nov 3 08:58:04 EDT 2010
On 11/02/2010 23:15, Tom Van Baak wrote:
> So how about having a Leap Second Every Month (LSEM)?
> The definition of UTC doesn't even need to be changed. The
> only question for the IERS each month is if the leap will be
> positive or negative. But there is always a leap; with one or
> many months of notice. It's only 12-bits of data a year. This
> can be disseminated in a modern way (internet).
> No secular drift. No religious objections. No redefinition of
> UTC. No change to WWVB. No change to GPS. No change
> to NTP. No more silly leap second newspapers articles. Way
> more opportunities for software to be written correctly the
> first time. Wider public knowledge and understanding of leap
> seconds. The impetus for creating well-architected internet
> leap second information services. Closer tracking of UT1.
> Greater ability to handle unusual earth accel/deceleration
> episodes.
>
The reference ntp implementation from udel currently has a filter in its
leap second code that restricts leap seconds to June and December.
Many older GPS steered clocks have filters as well that restrict things
to Dec/June and sometimes Mar/Sept.
Some software that listens to WWVB broadcasts "knows" that a leap
indicator means "there will be a leap at the end of December or June."
Not the end of the month. This is a small semantic change. A few years
ago, there were a few of these kinds of broadcast systems knocking about.
Most people will argue with you that this is a change to UTC, despite
monthly leap seconds being in the definition :)
I kinda like the idea, but only if you could publish the leap seconds
years in advance :)
Warner
More information about the LEAPSECS
mailing list