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Historical fix for Tonga
by Tim Parenti Sept. 14, 2021

Sept. 14, 2021

First, a quick clerical patch: 0001, attached, fixes the placement of a comment which got shuffled around in the lead-up to publishing the changes for South Sudan in 2021a. Patch 0003 relates to Tonga, and comes from some of the links P Chan shared to 1957–1963 editions of The Air Almanac: https://mm.icann.org/pipermail/tz/2021-February/029866.html On Thu, 25 Feb 2021 at 03:43, P Chan <legco(a)outlook.com> wrote: > 1960 Nov (1962.1-4) > https://books.google.com/books?id=bVgtWM6kPZUC&pg=SL1-PA20 > 1961 Mar (1962.5-8) > https://books.google.com/books?id=W2nItAul4g0C&pg=SL1-PA20 When looking around at how this data was presented for other regions, I noticed on the preceding pages (listing "Places Fast on GMT", i.e., east of Greenwich) in some of the earlier editions provided that Tonga was listed at GMT+12:20. The peculiar offset stuck out, and I quickly noticed that some of the later editions of the same tables had it at GMT+13. A quick bisection puts the changeover, as far as The Air Almanac contemporaneously reckoned it, between November 1960 and March 1961. Previously, our data had Tonga transitioning to UT+13 in 1941 based on a quotation from a 1997 news article. Although this differs from what the Almanac suggests by some 20 years, the article does mention a change coincident with the New Year, and that Tāufaʻāhau Tupou IV was Crown Prince at the time. As his predecessor and mother, Queen Sālote Tupou III, reigned from 1918-04-05 to 1965-12-16, a possible transition of 1961-01-01 still jives with the gist of the article, even if the specific year was perhaps wrong or just misprinted. For what it's worth, our commentary already noted that Shanks & Pottenger had put the transition even later, at 1968-10-01. Although of course we don't know how they arrived at that date, given that they did, 1961 seems rather less out-of-place than it otherwise might. The attached patch 0003 makes this adjustment, while more fully documenting and comparing the conflicting sources. Thanks again to P Chan for pointing us to these resources. I wasn't expecting to get a "bonus" correction out of it, but one never knows quite what will catch the eye… -- Tim Parenti

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[PATCH 1/8] * tzfile.5: Fix prefix/suffix typo (thanks to Ian Abbott).
by Paul Eggert Sept. 14, 2021

Sept. 14, 2021

--- tzfile.5 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tzfile.5 b/tzfile.5 index b4952d5..ec78689 100644 --- a/tzfile.5 +++ b/tzfile.5 @@ -134,7 +134,7 @@ bytes that represent time zone designations, which are null-terminated byte strings, each indexed by the .B tt_desigidx values mentioned above. -The byte strings can overlap if one is a prefix of the other. +The byte strings can overlap if one is a suffix of the other. The encoding of these strings is not specified. .IP * .B tzh_leapcnt -- 2.27.0

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[PROPOSED] zic -r is incompatible with rolling leaps
by Paul Eggert Sept. 13, 2021

Sept. 13, 2021

* NEWS, zic.8: Mention this. * zic.c (leapadd): Report an error if the user tries it. --- NEWS | 3 +++ zic.8 | 3 +++ zic.c | 4 ++++ 3 files changed, 10 insertions(+) diff --git a/NEWS b/NEWS index 1b5535a..62a7ba2 100644 --- a/NEWS +++ b/NEWS @@ -137,6 +137,9 @@ Unreleased, experimental changes last time transition disagreed with the TZ string, contrary to Internet RFC 8563 section 3.3. + zic -r now reports an error if given rolling leap seconds, as this + usage has never generally worked and is evidently unused. + zic now generates a POSIX-conforming TZ string for TZif files where all-year DST is predicted for the indefinite future. For example, for all-year Eastern Daylight Time, zic now generates diff --git a/zic.8 b/zic.8 index b77841b..3023ebe 100644 --- a/zic.8 +++ b/zic.8 @@ -709,6 +709,9 @@ or .q "Rolling" if the leap second time given by the other fields should be interpreted as local (wall clock) time. +(Rolling leap seconds are not supported if the +.B \*-r +option is used.) .PP The expiration line, if present, has the form: .nf diff --git a/zic.c b/zic.c index e2a7e13..b06ef66 100644 --- a/zic.c +++ b/zic.c @@ -3144,6 +3144,10 @@ leapadd(zic_t t, int correction, int rolling) error(_("too many leap seconds")); exit(EXIT_FAILURE); } + if (rolling && (lo_time != min_time || hi_time != max_time)) { + error(_("Rolling leap seconds not supported with -r")); + exit(EXIT_FAILURE); + } for (i = 0; i < leapcnt; ++i) if (t <= trans[i]) break; -- 2.30.2

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Re: [tz] [PROPOSED] Fix ambiguous leapsecs by rolling up to a minute
by Paul Eggert Sept. 13, 2021

Sept. 13, 2021

On 9/13/21 2:45 AM, Robert Elz wrote: > do the changes in this proposal also correctly handle negative > leap seconds that are (for whatever bizarre reason) shoved into the middle > of a minute? Good question. I don't know of any problems in that area, though, as the proposed change does not affect negative leap seconds. The problem with 2021a and earlier is that localtime labels are ambiguous in a positive leap second inserted into the middle of a localtime minute; for example, if a leap second is inserted between seconds 11 and 12 the count is ... 9, 10, 11, 11, 12, 13,... which is problematic. With a negative leap second, the clock skips a second so there can be no ambiguity and there is no need for a fix. If the 11th second is skipped, for example, the localtime seconds is simply ... 9, 10, 12, 13,.... This has long been the case in the code, and the proposed change does not affect this.

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[PROPOSED] Simplify zic's handling of -r
by Paul Eggert Sept. 13, 2021

Sept. 13, 2021

This is refactoring; it should not affect user-visible behavior. * zic.c (struct timerange): New member pretrans. (limitrange): New arg locut. Use it to set r.pretrans. All callers changed. (writezone): Initialize the new member, to avoid undefined behavior. Simplify by using the new member. --- zic.c | 70 +++++++++++++++++++++++++++++------------------------------ 1 file changed, 34 insertions(+), 36 deletions(-) diff --git a/zic.c b/zic.c index a4406cb..e2a7e13 100644 --- a/zic.c +++ b/zic.c @@ -1958,29 +1958,44 @@ struct timerange { int defaulttype; ptrdiff_t base, count; int leapbase, leapcount; - bool leapexpiry; + bool pretrans, leapexpiry; }; static struct timerange -limitrange(struct timerange r, zic_t lo, zic_t hi, +limitrange(struct timerange r, bool locut, zic_t lo, zic_t hi, zic_t const *ats, unsigned char const *types) { + /* Omit ordinary transitions < LO. */ while (0 < r.count && ats[r.base] < lo) { r.defaulttype = types[r.base]; r.count--; r.base++; } + + /* Omit as many leap seconds < LO as possible, such that the first + leap second in the truncated list is <= LO. */ while (1 < r.leapcount && trans[r.leapbase + 1] <= lo) { r.leapcount--; r.leapbase++; } + /* Omit ordinary and leap second transitions greater than HI + 1. */ if (hi < ZIC_MAX) { while (0 < r.count && hi + 1 < ats[r.base + r.count - 1]) r.count--; while (0 < r.leapcount && hi + 1 < trans[r.leapbase + r.leapcount - 1]) r.leapcount--; } + + /* Determine whether to keep the last too-low transition if no + transition is exactly at LO. The kept transition will be output + as a LO "transition"; see "Output a LO_TIME transition" below. + This is needed when the output is truncated at the start, and is + also useful when catering to buggy 32-bit clients that do not use + time type 0 for timestamps before the first transition. */ + r.pretrans = locut && ! (r.count && ats[r.base] == lo); + + /* Determine whether to append an expiration to the leap second table. */ r.leapexpiry = 0 <= leapexpires && leapexpires - 1 <= hi; return r; @@ -2092,9 +2107,11 @@ writezone(const char *const name, const char *const string, char version, rangeall.base = rangeall.leapbase = 0; rangeall.count = timecnt; rangeall.leapcount = leapcnt; - rangeall.leapexpiry = false; - range64 = limitrange(rangeall, lo_time, hi_time, ats, types); - range32 = limitrange(range64, INT32_MIN, INT32_MAX, ats, types); + rangeall.pretrans = rangeall.leapexpiry = false; + range64 = limitrange(rangeall, min_time < lo_time, + lo_time, hi_time, ats, types); + range32 = limitrange(range64, INT32_MIN < lo_time, + INT32_MIN, INT32_MAX, ats, types); /* TZif version 4 is needed if a no-op transition is appended to indicate the expiration of the leap second table, or if the first @@ -2129,7 +2146,7 @@ writezone(const char *const name, const char *const string, char version, register int thisleapi, thisleapcnt, thisleaplim; struct tzhead tzh; int currenttype, thisdefaulttype; - bool locut, hicut, thisleapexpiry; + bool hicut, pretrans, thisleapexpiry; zic_t lo; int old0; char omittype[TZ_MAX_TYPES]; @@ -2160,8 +2177,8 @@ writezone(const char *const name, const char *const string, char version, toomanytimes = thistimecnt >> 31 >> 1 != 0; thisleapi = range32.leapbase; thisleapcnt = range32.leapcount; + pretrans = range32.pretrans; thisleapexpiry = range32.leapexpiry; - locut = INT32_MIN < lo_time; hicut = hi_time < INT32_MAX; } else { thisdefaulttype = range64.defaulttype; @@ -2170,33 +2187,17 @@ writezone(const char *const name, const char *const string, char version, toomanytimes = thistimecnt >> 31 >> 31 >> 2 != 0; thisleapi = range64.leapbase; thisleapcnt = range64.leapcount; + pretrans = range64.pretrans; thisleapexpiry = range64.leapexpiry; - locut = min_time < lo_time; hicut = hi_time < max_time; } if (toomanytimes) error(_("too many transition times")); - /* Keep the last too-low transition if no transition is - exactly at LO. The kept transition will be output as - a LO "transition"; see "Output a LO_TIME transition" - below. This is needed when the output is truncated at - the start, and is also useful when catering to buggy - 32-bit clients that do not use time type 0 for - timestamps before the first transition. */ - if (0 < thistimei && ats[thistimei] != lo_time) { - thistimei--; - thistimecnt++; - locut = false; - } - thistimelim = thistimei + thistimecnt; - if (thistimecnt != 0) { - if (ats[thistimei] == lo_time) - locut = false; - if (hi_time < ZIC_MAX && ats[thistimelim - 1] == hi_time + 1) - hicut = false; - } + if (thistimecnt && hi_time < ZIC_MAX + && ats[thistimelim - 1] == hi_time + 1) + hicut = false; memset(omittype, true, typecnt); omittype[thisdefaulttype] = false; for (i = thistimei; i < thistimelim; i++) @@ -2291,11 +2292,9 @@ writezone(const char *const name, const char *const string, char version, indmap[desigidx[i]] = j; } if (pass == 1 && !want_bloat()) { - thisleapcnt = 0; - thisleapexpiry = false; - thistimecnt = - (locut + hicut); + pretrans = hicut = thisleapexpiry = false; + thistimecnt = thisleapcnt = 0; thistypecnt = thischarcnt = 1; - thistimelim = thistimei; } #define DO(field) fwrite(tzh.field, sizeof tzh.field, 1, fp) memset(&tzh, 0, sizeof tzh); @@ -2304,7 +2303,7 @@ writezone(const char *const name, const char *const string, char version, convert(utcnt, tzh.tzh_ttisutcnt); convert(stdcnt, tzh.tzh_ttisstdcnt); convert(thisleapcnt + thisleapexpiry, tzh.tzh_leapcnt); - convert(locut + thistimecnt + hicut, tzh.tzh_timecnt); + convert(pretrans + thistimecnt + hicut, tzh.tzh_timecnt); convert(thistypecnt, tzh.tzh_typecnt); convert(thischarcnt, tzh.tzh_charcnt); DO(tzh_magic); @@ -2331,16 +2330,15 @@ writezone(const char *const name, const char *const string, char version, for this pass. */ lo = pass == 1 && lo_time < INT32_MIN ? INT32_MIN : lo_time; - if (locut) + if (pretrans) puttzcodepass(lo, fp, pass); for (i = thistimei; i < thistimelim; ++i) { - zic_t at = ats[i] < lo ? lo : ats[i]; - puttzcodepass(at, fp, pass); + puttzcodepass(ats[i], fp, pass); } if (hicut) puttzcodepass(hi_time + 1, fp, pass); currenttype = 0; - if (locut) + if (pretrans) putc(currenttype, fp); for (i = thistimei; i < thistimelim; ++i) { currenttype = typemap[types[i]]; -- 2.31.1

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[PATCH] Use https: for opengroup in zic.8
by Paul Eggert Sept. 12, 2021

Sept. 12, 2021

--- zic.8 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/zic.8 b/zic.8 index 800fb8b..b77841b 100644 --- a/zic.8 +++ b/zic.8 @@ -252,7 +252,7 @@ zero or more lines, each ending in a newline byte and containing at most 511 bytes, and without any NUL bytes. The input text's encoding is typically UTF-8 or ASCII; it should have a unibyte representation for the POSIX Portable Character Set (PPCS) -\*<http://pubs\*:.opengroup\*:.org/\*:onlinepubs/\*:9699919799/\*:basedefs/\*:…> +\*<https://pubs\*:.opengroup\*:.org/\*:onlinepubs/\*:9699919799/\*:basedefs/\*…> and the encoding's non-unibyte characters should consist entirely of non-PPCS bytes. Non-PPCS characters typically occur only in comments: although output file names and time zone abbreviations can contain -- 2.31.1

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[PATCH] Port ‘check_time_t_alternatives’ to oddball hosts
by Paul Eggert Sept. 12, 2021

Sept. 12, 2021

* Makefile (TIME_T_ALTERNATIVES): Use int_least64_t instead of int64_t, as int64_t is not required by the C standard. Similarly for int32_t, uint32_t, uint64_t. --- Makefile | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/Makefile b/Makefile index b00ac05..8a7436a 100644 --- a/Makefile +++ b/Makefile @@ -122,8 +122,8 @@ LIBDIR = $(TOPDIR)/$(USRDIR)/lib # Types to try, as an alternative to time_t. TIME_T_ALTERNATIVES = $(TIME_T_ALTERNATIVES_HEAD) $(TIME_T_ALTERNATIVES_TAIL) -TIME_T_ALTERNATIVES_HEAD = int64_t -TIME_T_ALTERNATIVES_TAIL = int32_t uint32_t uint64_t +TIME_T_ALTERNATIVES_HEAD = int_least64_t +TIME_T_ALTERNATIVES_TAIL = int_least32_t uint_least32_t uint_least64_t # What kind of TZif data files to generate. (TZif is the binary time # zone data format that zic generates; see Internet RFC 8536.) @@ -976,7 +976,7 @@ $(TIME_T_ALTERNATIVES): $(VERSION_DEPS) mkdir $@.dir ln $(VERSION_DEPS) $@.dir case $@ in \ - int32_t) range=-2147483648,2147483648;; \ + int*32_t) range=-2147483648,2147483648;; \ u*) range=0,4294967296;; \ *) range=-4294967296,4294967296;; \ esac && \ -- 2.31.1

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request
by Cool Gab19 Sept. 12, 2021

Sept. 12, 2021

I request Etc/GMT-15 or +15 be included in your database https://github.com/gabtimezone15/tz/blob/d0970deeac9041a1e8a585782ccec3a1ef…

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[PROPOSED] Omit some casts
by Paul Eggert Sept. 11, 2021

Sept. 11, 2021

* localtime.c (getsecs, localsub, timesub): * strftime.c (_fmt): * zdump.c (dumptime): * zic.c (rcomp, atcomp): Rely on automatic conversions instead of casts, which are more error-prone. --- localtime.c | 13 +++++++------ strftime.c | 12 +++++++----- zdump.c | 17 ++++++----------- zic.c | 11 +++++------ 4 files changed, 25 insertions(+), 28 deletions(-) diff --git a/localtime.c b/localtime.c index cc972ef..88fd35d 100644 --- a/localtime.c +++ b/localtime.c @@ -862,6 +862,7 @@ static const char * getsecs(register const char *strp, int_fast32_t *const secsp) { int num; + int_fast32_t secsperhour = SECSPERHOUR; /* ** 'HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like @@ -872,7 +873,7 @@ getsecs(register const char *strp, int_fast32_t *const secsp) strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1); if (strp == NULL) return NULL; - *secsp = num * (int_fast32_t) SECSPERHOUR; + *secsp = num * secsperhour; if (*strp == ':') { ++strp; strp = getnum(strp, &num, 0, MINSPERHOUR - 1); @@ -1544,7 +1545,7 @@ localsub(struct state const *sp, time_t const *timep, int_fast32_t setname, hi = mid; else lo = mid + 1; } - i = (int) sp->types[lo - 1]; + i = sp->types[lo - 1]; } ttisp = &sp->ttis[i]; /* @@ -1757,18 +1758,18 @@ timesub(const time_t *timep, int_fast32_t offset, tmp->tm_wday %= DAYSPERWEEK; if (tmp->tm_wday < 0) tmp->tm_wday += DAYSPERWEEK; - tmp->tm_hour = (int) (rem / SECSPERHOUR); + tmp->tm_hour = rem / SECSPERHOUR; rem %= SECSPERHOUR; - tmp->tm_min = (int) (rem / SECSPERMIN); + tmp->tm_min = rem / SECSPERMIN; /* ** A positive leap second requires a special ** representation. This uses "... ??:59:60" et seq. */ - tmp->tm_sec = (int) (rem % SECSPERMIN) + hit; + tmp->tm_sec = rem % SECSPERMIN + hit; ip = mon_lengths[isleap(y)]; for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon)) idays -= ip[tmp->tm_mon]; - tmp->tm_mday = (int) (idays + 1); + tmp->tm_mday = idays + 1; tmp->tm_isdst = 0; #ifdef TM_GMTOFF tmp->TM_GMTOFF = offset; diff --git a/strftime.c b/strftime.c index 4f871cd..5273155 100644 --- a/strftime.c +++ b/strftime.c @@ -335,11 +335,13 @@ label: && tm.tm_sec == tm_1.tm_sec)) return NULL; } - if (TYPE_SIGNED(time_t)) - sprintf(buf, "%"PRIdMAX, - (intmax_t) mkt); - else sprintf(buf, "%"PRIuMAX, - (uintmax_t) mkt); + if (TYPE_SIGNED(time_t)) { + intmax_t n = mkt; + sprintf(buf, "%"PRIdMAX, n); + } else { + uintmax_t n = mkt; + sprintf(buf, "%"PRIuMAX, n); + } pt = _add(buf, pt, ptlim); } continue; diff --git a/zdump.c b/zdump.c index 9d22b26..e198b04 100644 --- a/zdump.c +++ b/zdump.c @@ -1155,8 +1155,6 @@ dumptime(register const struct tm *timeptr) "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" }; - register const char * wn; - register const char * mn; register int lead; register int trail; @@ -1169,16 +1167,13 @@ dumptime(register const struct tm *timeptr) ** values in tm_wday or tm_mon, but since this code might be compiled ** with other (perhaps experimental) versions, paranoia is in order. */ - if (timeptr->tm_wday < 0 || timeptr->tm_wday >= - (int) (sizeof wday_name / sizeof wday_name[0])) - wn = "???"; - else wn = wday_name[timeptr->tm_wday]; - if (timeptr->tm_mon < 0 || timeptr->tm_mon >= - (int) (sizeof mon_name / sizeof mon_name[0])) - mn = "???"; - else mn = mon_name[timeptr->tm_mon]; printf("%s %s%3d %.2d:%.2d:%.2d ", - wn, mn, + ((0 <= timeptr->tm_wday + && timeptr->tm_wday < sizeof wday_name / sizeof wday_name[0]) + ? wday_name[timeptr->tm_wday] : "???"), + ((0 <= timeptr->tm_mon + && timeptr->tm_mon < sizeof mon_name / sizeof mon_name[0]) + ? mon_name[timeptr->tm_mon] : "???"), timeptr->tm_mday, timeptr->tm_hour, timeptr->tm_min, timeptr->tm_sec); #define DIVISOR 10 diff --git a/zic.c b/zic.c index 4c55f1c..a4406cb 100644 --- a/zic.c +++ b/zic.c @@ -1225,8 +1225,8 @@ itssymlink(char const *name) static int rcomp(const void *cp1, const void *cp2) { - return strcmp(((const struct rule *) cp1)->r_name, - ((const struct rule *) cp2)->r_name); + struct rule const *r1 = cp1, *r2 = cp2; + return strcmp(r1->r_name, r2->r_name); } static void @@ -1949,10 +1949,9 @@ puttzcodepass(zic_t val, FILE *fp, int pass) static int atcomp(const void *avp, const void *bvp) { - const zic_t a = ((const struct attype *) avp)->at; - const zic_t b = ((const struct attype *) bvp)->at; - - return (a < b) ? -1 : (a > b); + struct attype const *ap = avp, *bp = bvp; + zic_t a = ap->at, b = bp->at; + return a < b ? -1 : a > b; } struct timerange { -- 2.31.1

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[PATCH] Fix tzfile.h comment
by Paul Eggert Sept. 11, 2021

Sept. 11, 2021

* tzfile.h (struct tzhead): Update comment for version 4. --- tzfile.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tzfile.h b/tzfile.h index ee91104..9c3ea4e 100644 --- a/tzfile.h +++ b/tzfile.h @@ -44,7 +44,7 @@ struct tzhead { char tzh_magic[4]; /* TZ_MAGIC */ - char tzh_version[1]; /* '\0' or '2' or '3' as of 2013 */ + char tzh_version[1]; /* '\0' or '2'-'4' as of 2021 */ char tzh_reserved[15]; /* reserved; must be zero */ char tzh_ttisutcnt[4]; /* coded number of trans. time flags */ char tzh_ttisstdcnt[4]; /* coded number of trans. time flags */ -- 2.31.1

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