1 /* GLIB - Library of useful routines for C programming
2 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
21 * Modified by the GLib Team and others 1997-2000. See the AUTHORS
22 * file for a list of people on the GLib Team. See the ChangeLog
23 * files for a list of changes. These files are distributed with
24 * GLib at ftp://ftp.gtk.org/pub/gtk/.
33 #define DEBUG_MSG(x) /* */
35 /* #define DEBUG_MSG(args) g_message args ; */
49 GDate *d = g_new0 (GDate, 1); /* happily, 0 is the invalid flag for everything. */
55 g_date_new_dmy (GDateDay day, GDateMonth m, GDateYear y)
58 g_return_val_if_fail (g_date_valid_dmy (day, m, y), NULL);
69 g_assert (g_date_valid (d));
75 g_date_new_julian (guint32 j)
78 g_return_val_if_fail (g_date_valid_julian (j), NULL);
87 g_assert (g_date_valid (d));
93 g_date_free (GDate *d)
95 g_return_if_fail (d != NULL);
101 g_date_valid (const GDate *d)
103 g_return_val_if_fail (d != NULL, FALSE);
105 return (d->julian || d->dmy);
108 static const guint8 days_in_months[2][13] =
109 { /* error, jan feb mar apr may jun jul aug sep oct nov dec */
110 { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
111 { 0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } /* leap year */
114 static const guint16 days_in_year[2][14] =
115 { /* 0, jan feb mar apr may jun jul aug sep oct nov dec */
116 { 0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
117 { 0, 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
121 g_date_valid_month (GDateMonth m)
123 return ( (m > G_DATE_BAD_MONTH) && (m < 13) );
127 g_date_valid_year (GDateYear y)
129 return ( y > G_DATE_BAD_YEAR );
133 g_date_valid_day (GDateDay d)
135 return ( (d > G_DATE_BAD_DAY) && (d < 32) );
139 g_date_valid_weekday (GDateWeekday w)
141 return ( (w > G_DATE_BAD_WEEKDAY) && (w < 8) );
145 g_date_valid_julian (guint32 j)
147 return (j > G_DATE_BAD_JULIAN);
151 g_date_valid_dmy (GDateDay d,
155 return ( (m > G_DATE_BAD_MONTH) &&
157 (d > G_DATE_BAD_DAY) &&
158 (y > G_DATE_BAD_YEAR) && /* must check before using g_date_is_leap_year */
159 (d <= (g_date_is_leap_year (y) ?
160 days_in_months[1][m] : days_in_months[0][m])) );
164 /* "Julian days" just means an absolute number of days, where Day 1 ==
168 g_date_update_julian (const GDate *const_d)
170 GDate *d = (GDate *) const_d;
174 g_return_if_fail (d != NULL);
175 g_return_if_fail (d->dmy);
176 g_return_if_fail (!d->julian);
177 g_return_if_fail (g_date_valid_dmy (d->day, d->month, d->year));
179 /* What we actually do is: multiply years * 365 days in the year,
180 * add the number of years divided by 4, subtract the number of
181 * years divided by 100 and add the number of years divided by 400,
182 * which accounts for leap year stuff. Code from Steffen Beyer's
186 year = d->year - 1; /* we know d->year > 0 since it's valid */
188 d->julian_days = year * 365U;
189 d->julian_days += (year >>= 2); /* divide by 4 and add */
190 d->julian_days -= (year /= 25); /* divides original # years by 100 */
191 d->julian_days += year >> 2; /* divides by 4, which divides original by 400 */
193 index = g_date_is_leap_year (d->year) ? 1 : 0;
195 d->julian_days += days_in_year[index][d->month] + d->day;
197 g_return_if_fail (g_date_valid_julian (d->julian_days));
203 g_date_update_dmy (const GDate *const_d)
205 GDate *d = (GDate *) const_d;
210 guint32 A, B, C, D, E, M;
212 g_return_if_fail (d != NULL);
213 g_return_if_fail (d->julian);
214 g_return_if_fail (!d->dmy);
215 g_return_if_fail (g_date_valid_julian (d->julian_days));
217 /* Formula taken from the Calendar FAQ; the formula was for the
218 * Julian Period which starts on 1 January 4713 BC, so we add
219 * 1,721,425 to the number of days before doing the formula.
221 * I'm sure this can be simplified for our 1 January 1 AD period
222 * start, but I can't figure out how to unpack the formula.
225 A = d->julian_days + 1721425 + 32045;
226 B = ( 4 *(A + 36524) )/ 146097 - 1;
227 C = A - (146097 * B)/4;
228 D = ( 4 * (C + 365) ) / 1461 - 1;
229 E = C - ((1461*D) / 4);
230 M = (5 * (E - 1) + 2)/153;
232 m = M + 3 - (12*(M/10));
233 day = E - (153*M + 2)/5;
234 y = 100 * B + D - 4800 + (M/10);
236 #ifdef G_ENABLE_DEBUG
237 if (!g_date_valid_dmy (day, m, y))
239 g_warning ("\nOOPS julian: %u computed dmy: %u %u %u\n",
240 d->julian_days, day, m, y);
252 g_date_get_weekday (const GDate *d)
254 g_return_val_if_fail (g_date_valid (d), G_DATE_BAD_WEEKDAY);
258 g_date_update_julian (d);
260 g_return_val_if_fail (d->julian, G_DATE_BAD_WEEKDAY);
262 return ((d->julian_days - 1) % 7) + 1;
266 g_date_get_month (const GDate *d)
268 g_return_val_if_fail (g_date_valid (d), G_DATE_BAD_MONTH);
272 g_date_update_dmy (d);
274 g_return_val_if_fail (d->dmy, G_DATE_BAD_MONTH);
280 g_date_get_year (const GDate *d)
282 g_return_val_if_fail (g_date_valid (d), G_DATE_BAD_YEAR);
286 g_date_update_dmy (d);
288 g_return_val_if_fail (d->dmy, G_DATE_BAD_YEAR);
294 g_date_get_day (const GDate *d)
296 g_return_val_if_fail (g_date_valid (d), G_DATE_BAD_DAY);
300 g_date_update_dmy (d);
302 g_return_val_if_fail (d->dmy, G_DATE_BAD_DAY);
308 g_date_get_julian (const GDate *d)
310 g_return_val_if_fail (g_date_valid (d), G_DATE_BAD_JULIAN);
314 g_date_update_julian (d);
316 g_return_val_if_fail (d->julian, G_DATE_BAD_JULIAN);
318 return d->julian_days;
322 g_date_get_day_of_year (const GDate *d)
326 g_return_val_if_fail (g_date_valid (d), 0);
330 g_date_update_dmy (d);
332 g_return_val_if_fail (d->dmy, 0);
334 index = g_date_is_leap_year (d->year) ? 1 : 0;
336 return (days_in_year[index][d->month] + d->day);
340 g_date_get_monday_week_of_year (const GDate *d)
346 g_return_val_if_fail (g_date_valid (d), 0);
350 g_date_update_dmy (d);
352 g_return_val_if_fail (d->dmy, 0);
354 g_date_clear (&first, 1);
356 g_date_set_dmy (&first, 1, 1, d->year);
358 wd = g_date_get_weekday (&first) - 1; /* make Monday day 0 */
359 day = g_date_get_day_of_year (d) - 1;
361 return ((day + wd)/7U + (wd == 0 ? 1 : 0));
365 g_date_get_sunday_week_of_year (const GDate *d)
371 g_return_val_if_fail (g_date_valid (d), 0);
375 g_date_update_dmy (d);
377 g_return_val_if_fail (d->dmy, 0);
379 g_date_clear (&first, 1);
381 g_date_set_dmy (&first, 1, 1, d->year);
383 wd = g_date_get_weekday (&first);
384 if (wd == 7) wd = 0; /* make Sunday day 0 */
385 day = g_date_get_day_of_year (d) - 1;
387 return ((day + wd)/7U + (wd == 0 ? 1 : 0));
391 * g_date_get_iso8601_week_of_year:
392 * @date: a valid #GDate
394 * Returns the week of the year, where weeks are interpreted according
397 * Returns: ISO 8601 week number of the year.
402 g_date_get_iso8601_week_of_year (const GDate *d)
404 guint j, d4, L, d1, w;
406 g_return_val_if_fail (g_date_valid (d), 0);
409 g_date_update_julian (d);
410 g_return_val_if_fail (d->julian, 0);
412 /* Formula taken from the Calendar FAQ; the formula was for the
413 * Julian Period which starts on 1 January 4713 BC, so we add
414 * 1,721,425 to the number of days before doing the formula.
416 j = d->julian + 1721425;
417 d4 = (j + 31741 - (j % 7)) % 146097 % 36524 % 1461;
419 d1 = ((d4 - L) % 365) + L;
426 g_date_days_between (const GDate *d1,
429 g_return_val_if_fail (g_date_valid (d1), 0);
430 g_return_val_if_fail (g_date_valid (d2), 0);
432 return (gint)g_date_get_julian (d2) - (gint)g_date_get_julian (d1);
436 g_date_clear (GDate *d, guint ndates)
438 g_return_if_fail (d != NULL);
439 g_return_if_fail (ndates != 0);
441 memset (d, 0x0, ndates*sizeof (GDate));
444 G_LOCK_DEFINE_STATIC (g_date_global);
446 /* These are for the parser, output to the user should use *
447 * g_date_strftime () - this creates more never-freed memory to annoy
448 * all those memory debugger users. :-)
451 static gchar *long_month_names[13] =
453 "Error", NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
456 static gchar *short_month_names[13] =
458 "Error", NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
461 /* This tells us if we need to update the parse info */
462 static gchar *current_locale = NULL;
464 /* order of these in the current locale */
465 static GDateDMY dmy_order[3] =
467 G_DATE_DAY, G_DATE_MONTH, G_DATE_YEAR
470 /* Where to chop two-digit years: i.e., for the 1930 default, numbers
471 * 29 and below are counted as in the year 2000, numbers 30 and above
472 * are counted as in the year 1900.
475 static GDateYear twodigit_start_year = 1930;
477 /* It is impossible to enter a year between 1 AD and 99 AD with this
480 static gboolean using_twodigit_years = FALSE;
482 /* Adjustment of locale era to AD, non-zero means using locale era
484 static gint locale_era_adjust = 0;
486 struct _GDateParseTokens {
492 typedef struct _GDateParseTokens GDateParseTokens;
496 /* HOLDS: g_date_global_lock */
498 g_date_fill_parse_tokens (const gchar *str, GDateParseTokens *pt)
500 gchar num[4][NUM_LEN+1];
504 /* We count 4, but store 3; so we can give an error
507 num[0][0] = num[1][0] = num[2][0] = num[3][0] = '\0';
509 s = (const guchar *) str;
511 while (*s && pt->num_ints < 4)
515 while (*s && g_ascii_isdigit (*s) && i <= NUM_LEN)
517 num[pt->num_ints][i] = *s;
524 num[pt->num_ints][i] = '\0';
528 if (*s == '\0') break;
533 pt->n[0] = pt->num_ints > 0 ? atoi (num[0]) : 0;
534 pt->n[1] = pt->num_ints > 1 ? atoi (num[1]) : 0;
535 pt->n[2] = pt->num_ints > 2 ? atoi (num[2]) : 0;
537 pt->month = G_DATE_BAD_MONTH;
539 if (pt->num_ints < 3)
544 casefold = g_utf8_casefold (str, -1);
545 normalized = g_utf8_normalize (casefold, -1, G_NORMALIZE_ALL);
551 if (long_month_names[i] != NULL)
553 const gchar *found = strstr (normalized, long_month_names[i]);
562 if (short_month_names[i] != NULL)
564 const gchar *found = strstr (normalized, short_month_names[i]);
580 /* HOLDS: g_date_global_lock */
582 g_date_prepare_to_parse (const gchar *str, GDateParseTokens *pt)
584 const gchar *locale = setlocale (LC_TIME, NULL);
585 gboolean recompute_localeinfo = FALSE;
588 g_return_if_fail (locale != NULL); /* should not happen */
590 g_date_clear (&d, 1); /* clear for scratch use */
592 if ( (current_locale == NULL) || (strcmp (locale, current_locale) != 0) )
594 recompute_localeinfo = TRUE; /* Uh, there used to be a reason for the temporary */
597 if (recompute_localeinfo)
600 GDateParseTokens testpt;
603 g_free (current_locale); /* still works if current_locale == NULL */
605 current_locale = g_strdup (locale);
611 g_date_set_dmy (&d, 1, i, 1);
613 g_return_if_fail (g_date_valid (&d));
615 g_date_strftime (buf, 127, "%b", &d);
617 casefold = g_utf8_casefold (buf, -1);
618 g_free (short_month_names[i]);
619 short_month_names[i] = g_utf8_normalize (casefold, -1, G_NORMALIZE_ALL);
622 g_date_strftime (buf, 127, "%B", &d);
623 casefold = g_utf8_casefold (buf, -1);
624 g_free (long_month_names[i]);
625 long_month_names[i] = g_utf8_normalize (casefold, -1, G_NORMALIZE_ALL);
631 /* Determine DMY order */
633 /* had to pick a random day - don't change this, some strftimes
634 * are broken on some days, and this one is good so far. */
635 g_date_set_dmy (&d, 4, 7, 1976);
637 g_date_strftime (buf, 127, "%x", &d);
639 g_date_fill_parse_tokens (buf, &testpt);
642 while (i < testpt.num_ints)
647 dmy_order[i] = G_DATE_MONTH;
650 dmy_order[i] = G_DATE_DAY;
653 using_twodigit_years = TRUE; /* FALL THRU */
655 dmy_order[i] = G_DATE_YEAR;
658 /* assume locale era */
659 locale_era_adjust = 1976 - testpt.n[i];
660 dmy_order[i] = G_DATE_YEAR;
666 #ifdef G_ENABLE_DEBUG
667 DEBUG_MSG (("**GDate prepared a new set of locale-specific parse rules."));
671 DEBUG_MSG ((" %s %s", long_month_names[i], short_month_names[i]));
674 if (using_twodigit_years)
675 DEBUG_MSG (("**Using twodigit years with cutoff year: %u", twodigit_start_year));
681 switch (dmy_order[i])
684 strings[i] = "Month";
698 DEBUG_MSG (("**Order: %s, %s, %s", strings[0], strings[1], strings[2]));
699 DEBUG_MSG (("**Sample date in this locale: `%s'", buf));
704 g_date_fill_parse_tokens (str, pt);
708 g_date_set_parse (GDate *d,
712 guint m = G_DATE_BAD_MONTH, day = G_DATE_BAD_DAY, y = G_DATE_BAD_YEAR;
714 g_return_if_fail (d != NULL);
719 G_LOCK (g_date_global);
721 g_date_prepare_to_parse (str, &pt);
723 DEBUG_MSG (("Found %d ints, `%d' `%d' `%d' and written out month %d",
724 pt.num_ints, pt.n[0], pt.n[1], pt.n[2], pt.month));
727 if (pt.num_ints == 4)
729 G_UNLOCK (g_date_global);
730 return; /* presumably a typo; bail out. */
738 g_assert (pt.num_ints < 4); /* i.e., it is 2 or 3 */
740 while (i < pt.num_ints && j < 3)
742 switch (dmy_order[j])
746 if (pt.num_ints == 2 && pt.month != G_DATE_BAD_MONTH)
749 ++j; /* skip months, but don't skip this number */
758 if (pt.num_ints == 2 && pt.month == G_DATE_BAD_MONTH)
761 ++j; /* skip days, since we may have month/year */
771 if (locale_era_adjust != 0)
773 y += locale_era_adjust;
775 else if (using_twodigit_years && y < 100)
777 guint two = twodigit_start_year % 100;
778 guint century = (twodigit_start_year / 100) * 100;
796 if (pt.num_ints == 3 && !g_date_valid_dmy (day, m, y))
803 if (using_twodigit_years && y < 100)
804 y = G_DATE_BAD_YEAR; /* avoids ambiguity */
806 else if (pt.num_ints == 2)
808 if (m == G_DATE_BAD_MONTH && pt.month != G_DATE_BAD_MONTH)
814 else if (pt.num_ints == 1)
816 if (pt.month != G_DATE_BAD_MONTH)
818 /* Month name and year? */
825 /* Try yyyymmdd and yymmdd */
827 m = (pt.n[0]/100) % 100;
831 /* FIXME move this into a separate function */
832 if (using_twodigit_years && y < 100)
834 guint two = twodigit_start_year % 100;
835 guint century = (twodigit_start_year / 100) * 100;
845 /* See if we got anything valid out of all this. */
846 /* y < 8000 is to catch 19998 style typos; the library is OK up to 65535 or so */
847 if (y < 8000 && g_date_valid_dmy (day, m, y))
854 #ifdef G_ENABLE_DEBUG
856 DEBUG_MSG (("Rejected DMY %u %u %u", day, m, y));
858 G_UNLOCK (g_date_global);
862 g_date_set_time (GDate *d,
868 g_return_if_fail (d != NULL);
870 #ifdef HAVE_LOCALTIME_R
871 localtime_r (&t, &tm);
874 struct tm *ptm = localtime (&t);
878 /* Happens at least in Microsoft's C library if you pass a
879 * negative time_t. Use 2000-01-01 as default date.
881 #ifndef G_DISABLE_CHECKS
882 g_return_if_fail_warning (G_LOG_DOMAIN, "g_date_set_time", "ptm != NULL");
890 memcpy ((void *) &tm, (void *) ptm, sizeof(struct tm));
896 d->month = tm.tm_mon + 1;
898 d->year = tm.tm_year + 1900;
900 g_return_if_fail (g_date_valid_dmy (d->day, d->month, d->year));
906 g_date_set_month (GDate *d,
909 g_return_if_fail (d != NULL);
910 g_return_if_fail (g_date_valid_month (m));
912 if (d->julian && !d->dmy) g_date_update_dmy(d);
917 if (g_date_valid_dmy (d->day, d->month, d->year))
924 g_date_set_day (GDate *d,
927 g_return_if_fail (d != NULL);
928 g_return_if_fail (g_date_valid_day (day));
930 if (d->julian && !d->dmy) g_date_update_dmy(d);
935 if (g_date_valid_dmy (d->day, d->month, d->year))
942 g_date_set_year (GDate *d,
945 g_return_if_fail (d != NULL);
946 g_return_if_fail (g_date_valid_year (y));
948 if (d->julian && !d->dmy) g_date_update_dmy(d);
953 if (g_date_valid_dmy (d->day, d->month, d->year))
960 g_date_set_dmy (GDate *d,
965 g_return_if_fail (d != NULL);
966 g_return_if_fail (g_date_valid_dmy (day, m, y));
978 g_date_set_julian (GDate *d, guint32 j)
980 g_return_if_fail (d != NULL);
981 g_return_if_fail (g_date_valid_julian (j));
990 g_date_is_first_of_month (const GDate *d)
992 g_return_val_if_fail (g_date_valid (d), FALSE);
996 g_date_update_dmy (d);
998 g_return_val_if_fail (d->dmy, FALSE);
1000 if (d->day == 1) return TRUE;
1005 g_date_is_last_of_month (const GDate *d)
1009 g_return_val_if_fail (g_date_valid (d), FALSE);
1013 g_date_update_dmy (d);
1015 g_return_val_if_fail (d->dmy, FALSE);
1017 index = g_date_is_leap_year (d->year) ? 1 : 0;
1019 if (d->day == days_in_months[index][d->month]) return TRUE;
1024 g_date_add_days (GDate *d, guint ndays)
1026 g_return_if_fail (g_date_valid (d));
1030 g_date_update_julian (d);
1032 g_return_if_fail (d->julian);
1034 d->julian_days += ndays;
1039 g_date_subtract_days (GDate *d, guint ndays)
1041 g_return_if_fail (g_date_valid (d));
1045 g_date_update_julian (d);
1047 g_return_if_fail (d->julian);
1048 g_return_if_fail (d->julian_days > ndays);
1050 d->julian_days -= ndays;
1055 g_date_add_months (GDate *d,
1058 guint years, months;
1061 g_return_if_fail (g_date_valid (d));
1065 g_date_update_dmy (d);
1067 g_return_if_fail (d->dmy);
1069 nmonths += d->month - 1;
1072 months = nmonths%12;
1074 d->month = months + 1;
1077 index = g_date_is_leap_year (d->year) ? 1 : 0;
1079 if (d->day > days_in_months[index][d->month])
1080 d->day = days_in_months[index][d->month];
1084 g_return_if_fail (g_date_valid (d));
1088 g_date_subtract_months (GDate *d,
1091 guint years, months;
1094 g_return_if_fail (g_date_valid (d));
1098 g_date_update_dmy (d);
1100 g_return_if_fail (d->dmy);
1103 months = nmonths%12;
1105 g_return_if_fail (d->year > years);
1109 if (d->month > months) d->month -= months;
1113 d->month = 12 - months;
1117 index = g_date_is_leap_year (d->year) ? 1 : 0;
1119 if (d->day > days_in_months[index][d->month])
1120 d->day = days_in_months[index][d->month];
1124 g_return_if_fail (g_date_valid (d));
1128 g_date_add_years (GDate *d,
1131 g_return_if_fail (g_date_valid (d));
1135 g_date_update_dmy (d);
1137 g_return_if_fail (d->dmy);
1141 if (d->month == 2 && d->day == 29)
1143 if (!g_date_is_leap_year (d->year))
1153 g_date_subtract_years (GDate *d,
1156 g_return_if_fail (g_date_valid (d));
1160 g_date_update_dmy (d);
1162 g_return_if_fail (d->dmy);
1163 g_return_if_fail (d->year > nyears);
1167 if (d->month == 2 && d->day == 29)
1169 if (!g_date_is_leap_year (d->year))
1180 g_date_is_leap_year (GDateYear year)
1182 g_return_val_if_fail (g_date_valid_year (year), FALSE);
1184 return ( (((year % 4) == 0) && ((year % 100) != 0)) ||
1185 (year % 400) == 0 );
1189 g_date_get_days_in_month (GDateMonth month,
1194 g_return_val_if_fail (g_date_valid_year (year), 0);
1195 g_return_val_if_fail (g_date_valid_month (month), 0);
1197 index = g_date_is_leap_year (year) ? 1 : 0;
1199 return days_in_months[index][month];
1203 g_date_get_monday_weeks_in_year (GDateYear year)
1207 g_return_val_if_fail (g_date_valid_year (year), 0);
1209 g_date_clear (&d, 1);
1210 g_date_set_dmy (&d, 1, 1, year);
1211 if (g_date_get_weekday (&d) == G_DATE_MONDAY) return 53;
1212 g_date_set_dmy (&d, 31, 12, year);
1213 if (g_date_get_weekday (&d) == G_DATE_MONDAY) return 53;
1214 if (g_date_is_leap_year (year))
1216 g_date_set_dmy (&d, 2, 1, year);
1217 if (g_date_get_weekday (&d) == G_DATE_MONDAY) return 53;
1218 g_date_set_dmy (&d, 30, 12, year);
1219 if (g_date_get_weekday (&d) == G_DATE_MONDAY) return 53;
1225 g_date_get_sunday_weeks_in_year (GDateYear year)
1229 g_return_val_if_fail (g_date_valid_year (year), 0);
1231 g_date_clear (&d, 1);
1232 g_date_set_dmy (&d, 1, 1, year);
1233 if (g_date_get_weekday (&d) == G_DATE_SUNDAY) return 53;
1234 g_date_set_dmy (&d, 31, 12, year);
1235 if (g_date_get_weekday (&d) == G_DATE_SUNDAY) return 53;
1236 if (g_date_is_leap_year (year))
1238 g_date_set_dmy (&d, 2, 1, year);
1239 if (g_date_get_weekday (&d) == G_DATE_SUNDAY) return 53;
1240 g_date_set_dmy (&d, 30, 12, year);
1241 if (g_date_get_weekday (&d) == G_DATE_SUNDAY) return 53;
1247 g_date_compare (const GDate *lhs,
1250 g_return_val_if_fail (lhs != NULL, 0);
1251 g_return_val_if_fail (rhs != NULL, 0);
1252 g_return_val_if_fail (g_date_valid (lhs), 0);
1253 g_return_val_if_fail (g_date_valid (rhs), 0);
1255 /* Remember the self-comparison case! I think it works right now. */
1260 if (lhs->julian && rhs->julian)
1262 if (lhs->julian_days < rhs->julian_days) return -1;
1263 else if (lhs->julian_days > rhs->julian_days) return 1;
1266 else if (lhs->dmy && rhs->dmy)
1268 if (lhs->year < rhs->year) return -1;
1269 else if (lhs->year > rhs->year) return 1;
1272 if (lhs->month < rhs->month) return -1;
1273 else if (lhs->month > rhs->month) return 1;
1276 if (lhs->day < rhs->day) return -1;
1277 else if (lhs->day > rhs->day) return 1;
1286 if (!lhs->julian) g_date_update_julian (lhs);
1287 if (!rhs->julian) g_date_update_julian (rhs);
1288 g_return_val_if_fail (lhs->julian, 0);
1289 g_return_val_if_fail (rhs->julian, 0);
1293 return 0; /* warnings */
1298 g_date_to_struct_tm (const GDate *d,
1303 g_return_if_fail (g_date_valid (d));
1304 g_return_if_fail (tm != NULL);
1308 g_date_update_dmy (d);
1310 g_return_if_fail (d->dmy);
1312 /* zero all the irrelevant fields to be sure they're valid */
1314 /* On Linux and maybe other systems, there are weird non-POSIX
1315 * fields on the end of struct tm that choke strftime if they
1316 * contain garbage. So we need to 0 the entire struct, not just the
1317 * fields we know to exist.
1320 memset (tm, 0x0, sizeof (struct tm));
1322 tm->tm_mday = d->day;
1323 tm->tm_mon = d->month - 1; /* 0-11 goes in tm */
1324 tm->tm_year = ((int)d->year) - 1900; /* X/Open says tm_year can be negative */
1326 day = g_date_get_weekday (d);
1327 if (day == 7) day = 0; /* struct tm wants days since Sunday, so Sunday is 0 */
1329 tm->tm_wday = (int)day;
1331 tm->tm_yday = g_date_get_day_of_year (d) - 1; /* 0 to 365 */
1332 tm->tm_isdst = -1; /* -1 means "information not available" */
1336 g_date_clamp (GDate *date,
1337 const GDate *min_date,
1338 const GDate *max_date)
1340 g_return_if_fail (g_date_valid (date));
1342 if (min_date != NULL)
1343 g_return_if_fail (g_date_valid (min_date));
1344 if (max_date != NULL)
1345 g_return_if_fail (g_date_valid (max_date));
1346 if (min_date != NULL && max_date != NULL)
1347 g_return_if_fail (g_date_compare (min_date, max_date) <= 0);
1349 if (min_date && g_date_compare (date, min_date) < 0)
1352 if (max_date && g_date_compare (max_date, date) < 0)
1357 g_date_order (GDate *date1,
1360 g_return_if_fail (g_date_valid (date1));
1361 g_return_if_fail (g_date_valid (date2));
1363 if (g_date_compare (date1, date2) > 0)
1372 g_date_strftime (gchar *s,
1374 const gchar *format,
1378 gsize locale_format_len = 0;
1379 gchar *locale_format;
1385 GError *error = NULL;
1388 g_return_val_if_fail (g_date_valid (d), 0);
1389 g_return_val_if_fail (slen > 0, 0);
1390 g_return_val_if_fail (format != 0, 0);
1391 g_return_val_if_fail (s != 0, 0);
1393 g_date_to_struct_tm (d, &tm);
1395 locale_format = g_locale_from_utf8 (format, -1, NULL, &locale_format_len, &error);
1399 g_warning (G_STRLOC "Error converting format to locale encoding: %s\n", error->message);
1400 g_error_free (error);
1406 tmpbufsize = MAX (128, locale_format_len * 2);
1409 tmpbuf = g_malloc (tmpbufsize);
1411 /* Set the first byte to something other than '\0', to be able to
1412 * recognize whether strftime actually failed or just returned "".
1415 tmplen = strftime (tmpbuf, tmpbufsize, locale_format, &tm);
1417 if (tmplen == 0 && tmpbuf[0] != '\0')
1422 if (tmpbufsize > 65536)
1424 g_warning (G_STRLOC "Maximum buffer size for g_date_strftime exceeded: giving up\n");
1425 g_free (locale_format);
1434 g_free (locale_format);
1436 convbuf = g_locale_to_utf8 (tmpbuf, tmplen, NULL, &convlen, &error);
1441 g_warning (G_STRLOC "Error converting results of strftime to UTF-8: %s\n", error->message);
1442 g_error_free (error);
1448 if (slen <= convlen)
1450 /* Ensure only whole characters are copied into the buffer.
1452 gchar *end = g_utf8_find_prev_char (convbuf, convbuf + slen);
1453 g_assert (end != NULL);
1454 convlen = end - convbuf;
1456 /* Return 0 because the buffer isn't large enough.
1463 memcpy (s, convbuf, convlen);