[LEAPSECS] The relation between calendars and leap seconds.

[Adi Stav]

On Mon, Nov 10, 2008 at 10:23:36PM -0700, Rob Seaman wrote:

> Adi Stav wrote:

>

>> On Mon, Nov 10, 2008 at 04:13:25PM +0000, Tony Finch wrote:

>>>

>>> I agree with your requirements 2,3,4 and I note that UTC doesn't  

>>> satisfy

>>> 3, which is another statement of this timeless predictability  

>>> requirement.

>>> (Your requirement 4 is only relatively timeless, since it allows for

>>> changes in the definition of the second.)

>>

>> Have there been suggestions, indeed, for such a predictable SI- 

>> second-based

>> calendar that synchronizes with the Earth's rotation?

>

>

> Well, that is the UTC that we have.  Two timescales, earth orientation  

> and interval.  Compromise a little on the SI part and a little on the  

> solar day part to jigger these two things into a single standard.


We don't how many seconds there will be in 2009-12-31 23:59; there
might be 60, 59, or 61. So the UTC calendar is not predictable.

I can easily imagine such predictable systems, such as adding "permenant 
leap seconds" regularly into the year according to some pre-determined 
formula, but I don't think I've every seen such a thing proposed.