On Jan 3, 2014, at 1:45 PM, Stephen Scott wrote: > Subject: Local insertion of leap seconds > > I am new to this group so please excuse if this subject has been previously > covered. > > As I understand the standard ITU-R TF.460-6 the leap second correction is > instantiated globally as the last second of a UTCZ month. > > However I have not been able to determine any practices for instantiating the > leap second correction at other times to avoid such an interruption in the > timescale at an inopportune time of day in different locations around the > world.
There are one. That's when the leap second happens. It is one of the problems with leap seconds. They are scheduled for a time that's convenient for Europe, not too bad for north/south america, and terrible for Asia. Warner > In countries west of Greenwich the insertion happens before midnight making > possible to delay the correction to a later and more appropriate time. > However in countries east of Greenwich the correction could need to have > sufficient advance notice. > > Can you enlighten my understanding of what practices may exist? > > Background for these concerns is compounded by a number of factors. > > 1.) Television broadcast automation requires precise timing to avoid > programs and in particular commercials from being clipped or having gaps. > 2.) Video in North America and some other parts of the world is generated > on a timescale that is at a frequency of 30/1.001 Hz. This deviation from a > SI second timescale means that a leap second insertion is > equivalent to inserting 29.97002997… video frames. > 3.) This rate implies in a non-integer number of video frames in a 24 hour > day and thus a varying phase alignment to a 24 hour clock. > > Regards > Stephen > > -- > Stephen Scott > Skotel Corporation > Brossard, Québec > Canada > Mobile: +1 514-806-2340 > Skype: SScott2645 > Email: [email protected] > > > > > > This email is free from viruses and malware because avast! Antivirus > protection is active. > > > _______________________________________________ > LEAPSECS mailing list > [email protected] > http://six.pairlist.net/mailman/listinfo/leapsecs _______________________________________________ LEAPSECS mailing list [email protected] http://six.pairlist.net/mailman/listinfo/leapsecs
