[LEAPSECS] one second tolerance

Poul-Henning Kamp phk at phk.freebsd.dk
Thu Feb 10 15:42:33 EST 2011

In message <4D544A0E.4020902 at yahoo.com>, Michael Deckers writes:


>> In Denmark the law used to say that you have to suffix the

>> timestamp with 'A' and 'B' during these two hours.


> Interesting. That notation still seems to be legal, see

> [http://www.retsinformation.dk/Forms/R0710.aspx?id=22064].

Yes, one interesting detail here is the use of the word "klokketiden"
which literally means "(Church-)Bell-Time", but which most people
would understand as "clock-time"

This word first appears in 1946 in the first law to introduce
DST in Denmark, and _presumably_, but we cannot know for sure,
this was meant to distinguish "clock time" from "solar time":

> However, I have never seen that notation being applied in

> practice in Germany, not even by the PTB. Has it ever been

> used on a perceivable level in Denmark?

I have only ever seen it once, and that was my own doing:

When we ran into this, We tried to see if we could fit
the 'A/B' designator on the receipt printed by the automatic
gas-pumps without using another line of text.

We couldn't and since we could not have a special print format
during that one hour a day, compliance would have used 138km more
paper per year.

Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

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