[LEAPSECS] presentations from AAS Future of Time sessions

[Ian Batten]

On 16 Jan 2014, at 11:38, Tom Van Baak <tvb at leapsecond.com> wrote:

> 

> Yes, the Multics clock is very much like the one UNIX adopted. GCOS used a more traditional date and time format: 36-bits for date (mmddyy in BCD)



> I want to echo what others have said on this list, that even I of all people, did not think about leap seconds when I went into the computer room or coded. 


There were 22 leap seconds between their introduction and the computing KT boundary of 1999-12-31-23-59-59, at which point a lot of old systems breathed
their (official) last.  It would be interesting to know what proportion of computers 1975--2000 had their clocks aligned to within +/- 22 seconds of anything, such
that ignoring leap second was anything other than a second-order effect.

Some obviously did: I worked on systems with a +/- 1s from GMT requirement (yes, GMT: we used UTC and hoped no-one noticed) and by about 1992 I had a stratum
one clock and was running NTP over the whole estate.   But the typical desktop, timeshare or batch machine of the era was running to the operators' watches
at boot plus quite severe clock drift thereafter.

ian