[LEAPSECS] What's the point?

Rob Seaman seaman at noao.edu
Tue Feb 15 00:46:32 EST 2011

What's the point?

Two links to refresh the discussion:

Paul Sheer wrote:

> I think what you will find is that there is no technical difference between moving leap seconds into TZ, and eliminating leap seconds and adjusting TZ.

Vast difference. Steve Allen's zoneinfo idea preserves universal time separate from the new (or refurbished) atomic timescale. On the other hand, the whole point of rubber timezones is to eradicate universal time.

I know everybody here revels in these technical bake-offs, but it risks losing the underlying issues in the underbrush. Issue number one: atomic time and mean solar time are two different things because SI-seconds and synodic days are inherently distinct measures of our days.

Two suggestions for real progress on these two inherently different timescales:

1) Honor the Torino consensus and call any new leap-less atomic timescale something other than "UTC".

2) Improve the UTC we have. The state of the art in predicting UT1 (and thus scheduling UTC) is described in:


The state of the art appears to be significantly better than a tenth second over 500 days. There is an ongoing successor project:


Combining these improved predictions with prudently relaxed DUT1 constraints should permit extending leap second scheduling to several years.

These steps can be taken today with no tedious international negotiations. With the ITU's sword of Damocles removed we (meaning the real community of timekeeping stakeholders that is much broader than the group here) can consider how best to implement our next generation timekeeping system(s), rather than how worst we can screw up the functional timekeeping we inherited from our betters.

*That's* the point!


More information about the LEAPSECS mailing list