From: Eric Hodel <drbrain@...7.net>
Date: 2012-07-25T02:44:48+09:00
Subject: [ruby-core:46734] Re: [ruby-trunk - Bug #6749] rdoc of Time class (incorrect explanation of leap seconds)

On Jul 23, 2012, at 11:52 PM, sto.mar@web.de wrote:
> UTC is based on the International *Atomic* Time (ITA) and therefore on the SI second definition. (A day is not exactly 86400 SI seconds long, so to avoid that mean solar time and UTC differ too much,
> leap seconds were introduced.)
> 
> Please change "is based on solar time" to "is based on atomic time".

The UTC second is the same as the SI second and tracks TAI, but is not allowed to drift from UT1 by more than 0.9 seconds.  This makes both statements true, but in different senses. (TAI for second duration and count, UT1 for daily human-scheduled activities)

Since we're talking about leap seconds here, the solar time reference seems most relevant. How about I change "is based on" to "tracks"? The Wikipedia reference should allow users to learn all the details.