On 2019-08-17 17:38, Howard Hinnant wrote:
On Aug 17, 2019, at 4:45 PM, Paul Eggert <eggert@cs.ucla.edu> wrote:
… the 'leapseconds' file, which nowadays is used more often than the direct approach, or at least that's my impression.
Here’s another data point for you: http://eel.is/c++draft/time.clock.utc.overview#1 This is the draft C++20 spec which specifies two clocks: 1. system_clock: Models Unix Time (does not count leap seconds). 2. utc_clock: Counts leap seconds. And provides bidirectional mappings between these two sets of time points. And the easiest way to implement that mapping is to read in the IANA tz leapseconds file.
WG14/C is looking at: http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2402.pdf which seems somewhat based on the POSIX standard. The POSIX Austin CSRG is discussing clarifying tm_isdst: https://www.mail-archive.com/search?q=time&l=austin-group-l%40opengroup.org and other issues. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised.