[tz] Java & Rearguard

Guy Harris guy at alum.mit.edu
Wed Jun 12 01:50:13 UTC 2019

On Jun 11, 2019, at 1:14 PM, Guy Harris <guy at alum.mit.edu> wrote:

> On Jun 11, 2019, at 1:51 AM, Andreas Schwab <schwab at suse.de> wrote:
>> That's what the rest of the world calls summer time.
> That's what the part of the world that turns their clocks forward in spring and summer calls summer time.

Or that's what the part of the world that turns their clocks forward in spring and summer, with the exception of the US and (English-speaking?) Canada, calls "summer time".

In any case, the point is that not all locales that do seasonal adjustment of time have "standard time" during the autumn and winter and "summer time" during the spring and summer; they might have "standard time" during the spring and summer, as the Republic of Ireland does.

> One API that the tzdb must support is the C localtime()/mktime() API.  As specified in ISO/IEC 9899:2011(E):

Neither ISO/IEC 9899:2018(E) nor the most recent draft I've seen of ISO/IEC 9899:202x(E):


say anything significantly different - they continue to speak of "Daylight Saving Time", but leave it unspecified what it means, so as not to explicitly *disallow* it meaning something other than "temporarily turning clocks forward for spring and summer".

Paul, would somebody have to be a member of the C standards committee, or join their mailing list, in order to say "maybe the name 'Daylight Saving Time'" should be removed, in favor of something that doesn't imply a seasonal change where the algorithm is change to turn clocks forward, given that the algorithm might be changed for reasons that aren't what's conventionally thought of as seasonal (e.g., Ramadan) or might be changed to turn clocks *backward* in the winter"?

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