[time-nuts] FW: Bulletin C number 30

Mike S mikes at flatsurface.com
Tue Jul 5 16:44:18 EDT 2005

At 03:15 PM 7/5/2005, Warner Losh wrote...
>UTC was intended to be a civil time.  It was thought that it would be
>best if it followed astronomical time.  Maybe that fundamental thought
>is just wrong.

No, it isn't. Since much law is based upon specific reference to solar time, UTC (with leap seconds) is exactly appropriate for civil purposes. In the US, for instance, legal time "shall be based on the mean solar time of the [varies by time zone] degree of longitude west from Greenwich". 15 USC Sec. 261. 

Should civil time (which is effectively linked to UTC) be separated from solar time, there will be significant costs and ambiguities introduced legally. 

There would be significant costs also users in the astronomical and celestial navigation realms. The US Government states: "The mariner is constantly tempted to rely solely on electronic systems. But electronic navigation systems are always subject to failure, and the professional mariner must never forget that the safety of his ship and crew may depend on skills that differ little from those practiced generations ago. Proficiency in conventional piloting and celestial navigation remains essential." The US Navy, in fact, still requires shipboard competency in celestial navigation.

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