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Diffstat (limited to 'theory.html')
| -rw-r--r-- | theory.html | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/theory.html b/theory.html index 2b14c51..56390ae 100644 --- a/theory.html +++ b/theory.html @@ -122,7 +122,7 @@ If geolocation information is available, a selection interface can locate the user on a timezone map or prioritize names that are geographically close. For an example selection interface, see the <code>tzselect</code> program in the <code><abbr>tz</abbr></code> code. -The <a href="http://cldr.unicode.org">Unicode Common Locale Data +The <a href="https://cldr.unicode.org">Unicode Common Locale Data Repository</a> contains data that may be useful for other selection interfaces; it maps timezone names like <code>Europe/Prague</code> to locale-dependent strings like "Prague", "Praha", "Прага", and "布拉格". @@ -571,7 +571,7 @@ in decreasing order of importance: locations while uninhabited. The leading '<code>-</code>' is a flag that the <abbr>UT</abbr> offset is in some sense undefined; this notation is derived - from <a href="https://tools.ietf.org/html/rfc3339">Internet + from <a href="https://datatracker.ietf.org/doc/html/rfc3339">Internet <abbr title="Request For Comments">RFC</abbr> 3339</a>. </li> </ul> @@ -624,7 +624,7 @@ Errors in the <code><abbr>tz</abbr></code> database arise from many sources: should be observed. In her 2015 book <cite><a - href="http://www.hup.harvard.edu/catalog.php?isbn=9780674286146">The + href="https://www.hup.harvard.edu/catalog.php?isbn=9780674286146">The Global Transformation of Time, 1870–1950</a></cite>, Vanessa Ogle writes "Outside of Europe and North America there was no system of time @@ -810,7 +810,7 @@ href="https://www.dissentmagazine.org/blog/booked-a-global-history-of-time-vanes See: Stephenson FR, Morrison LV, Hohenkerk CY. <a href="https://dx.doi.org/10.1098/rspa.2016.0404">Measurement of the Earth's rotation: 720 BC to AD 2015</a>. - <cite>Proc Royal Soc A</cite>. 2016 Dec 7;472:20160404. + <cite>Proc Royal Soc A</cite>. 2016;472:20160404. Also see: Espenak F. <a href="https://eclipse.gsfc.nasa.gov/SEhelp/uncertainty2004.html">Uncertainty in Delta T (ΔT)</a>. @@ -1036,7 +1036,7 @@ an older <code>zic</code>. and numeric data as described <a href="#POSIX">above</a>. The file's format is <dfn><abbr>TZif</abbr></dfn>, a timezone information format that contains binary data; see - <a href="https://tools.ietf.org/html/8536">Internet + <a href="https://datatracker.ietf.org/doc/html/8536">Internet <abbr>RFC</abbr> 8536</a>. The daylight saving time rules to be used for a particular timezone are encoded in the @@ -1064,11 +1064,12 @@ an older <code>zic</code>. </li> <li> The code supports platforms with a <abbr>UT</abbr> offset member - in <code>struct tm</code>, e.g., <code>tm_gmtoff</code>. - </li> - <li> - The code supports platforms with a time zone abbreviation member in - <code>struct tm</code>, e.g., <code>tm_zone</code>. + in <code>struct tm</code>, e.g., <code>tm_gmtoff</code>, + or with a time zone abbreviation member in + <code>struct tm</code>, e.g., <code>tm_zone</code>. As noted + in <a href="https://austingroupbugs.net/view.php?id=1533">Austin + Group defect 1533</a>, a future version of POSIX is planned to + require <code>tm_gmtoff</code> and <code>tm_zone</code>. </li> <li> Functions <code>tzalloc</code>, <code>tzfree</code>, @@ -1129,7 +1130,8 @@ The vestigial <abbr>API</abbr>s are: <abbr>API</abbr>s. Although it can still be used in arguments to <code>mktime</code> to disambiguate timestamps near - a <abbr>DST</abbr> transition when the clock jumps back, this + a <abbr>DST</abbr> transition when the clock jumps back on + platforms lacking <code>tm_gmtoff</code>, this disambiguation does not work when standard time itself jumps back, which can occur when a location changes to a time zone with a lesser <abbr>UT</abbr> offset. @@ -1277,7 +1279,7 @@ the operating system kernel clock as described in <a href="tz-link.html#precision">Precision timekeeping</a>, and this package by default installs a <samp>leapseconds</samp> file commonly used by -<a href="http://www.ntp.org"><abbr title="Network Time Protocol">NTP</abbr></a> +<a href="https://www.ntp.org"><abbr title="Network Time Protocol">NTP</abbr></a> software that adjusts the kernel clock. However, kernel-clock twiddling approximates UTC only roughly, and systems needing more-precise UTC can use this package's leap |