[LEAPSECS] one second tolerance

Michael Deckers michael.deckers at yahoo.com
Thu Feb 10 17:01:12 EST 2011

On 2011-02-10 20:42, Poul-Henning Kamp wrote about
the Danish summer time law:

> 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":

> http://ordnet.dk/ods/ordbog?query=klokketid

Very interesting indeed! "klokketiden" also shows up in
web sites of Greenland and Norway (bokmål). I do not know
enough Danish -- could it have a function similar to the
(US) English wall clock time?

He continued about the use of suffixes 'A' and 'B'
to distinguish between the "repeated" datetimes that
occur when a civil time scale is set back from summer
time to winter time:

> 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.

Which evidently wasn't worth it. I've heard objections against
the notation on the grounds that letter suffixes like A and B
are used in the military, where they denote fixed time zones
(Alpha for UTC + 1 h, Bravo for UTC + 2 h, ...).


Michael Deckers.

More information about the LEAPSECS mailing list