/ext/date/lib/dow.c
C | 164 lines | 112 code | 21 blank | 31 comment | 34 complexity | b7043d2242a34914eadb490439af3c84 MD5 | raw file
Possible License(s): MPL-2.0-no-copyleft-exception, LGPL-2.1, BSD-3-Clause
- /*
- +----------------------------------------------------------------------+
- | PHP Version 5 |
- +----------------------------------------------------------------------+
- | Copyright (c) 1997-2010 The PHP Group |
- +----------------------------------------------------------------------+
- | This source file is subject to version 3.01 of the PHP license, |
- | that is bundled with this package in the file LICENSE, and is |
- | available through the world-wide-web at the following url: |
- | http://www.php.net/license/3_01.txt |
- | If you did not receive a copy of the PHP license and are unable to |
- | obtain it through the world-wide-web, please send a note to |
- | license@php.net so we can mail you a copy immediately. |
- +----------------------------------------------------------------------+
- | Authors: Derick Rethans <derick@derickrethans.nl> |
- +----------------------------------------------------------------------+
- */
- /* $Id: dow.c 293036 2010-01-03 09:23:27Z sebastian $ */
- #include "timelib.h"
- static int m_table_common[13] = { -1, 0, 3, 3, 6, 1, 4, 6, 2, 5, 0, 3, 5 }; /* 1 = jan */
- static int m_table_leap[13] = { -1, 6, 2, 3, 6, 1, 4, 6, 2, 5, 0, 3, 5 }; /* 1 = jan */
- static timelib_sll century_value(timelib_sll j)
- {
- timelib_sll i = j - 17;
- timelib_sll c = (4 - i * 2 + (i + 1) / 4) % 7;
- return c < 0 ? c + 7 : c;
- }
- static timelib_sll timelib_day_of_week_ex(timelib_sll y, timelib_sll m, timelib_sll d, int iso)
- {
- timelib_sll c1, y1, m1, dow;
- /* Only valid for Gregorian calendar, commented out as we don't handle
- * julian calendar. We just return the 'wrong' day of week to be
- * consistent.
- if (y < 1753) {
- return -1;
- } */
- c1 = century_value(y / 100);
- y1 = (y % 100);
- m1 = timelib_is_leap(y) ? m_table_leap[m] : m_table_common[m];
- dow = (c1 + y1 + m1 + (y1 / 4) + d) % 7;
- if (iso) {
- if (dow == 0) {
- dow = 7;
- }
- }
- return dow;
- }
- timelib_sll timelib_day_of_week(timelib_sll y, timelib_sll m, timelib_sll d)
- {
- return timelib_day_of_week_ex(y, m, d, 0);
- }
- timelib_sll timelib_iso_day_of_week(timelib_sll y, timelib_sll m, timelib_sll d)
- {
- return timelib_day_of_week_ex(y, m, d, 1);
- }
- /* jan feb mar apr may jun jul aug sep oct nov dec */
- static int d_table_common[13] = { 0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
- static int d_table_leap[13] = { 0, 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335 };
- static int ml_table_common[13] = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
- static int ml_table_leap[13] = { 0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
- timelib_sll timelib_day_of_year(timelib_sll y, timelib_sll m, timelib_sll d)
- {
- return (timelib_is_leap(y) ? d_table_leap[m] : d_table_common[m]) + d - 1;
- }
- timelib_sll timelib_days_in_month(timelib_sll y, timelib_sll m)
- {
- return timelib_is_leap(y) ? ml_table_leap[m] : ml_table_common[m];
- }
- void timelib_isoweek_from_date(timelib_sll y, timelib_sll m, timelib_sll d, timelib_sll *iw, timelib_sll *iy)
- {
- int y_leap, prev_y_leap, doy, jan1weekday, weekday;
- y_leap = timelib_is_leap(y);
- prev_y_leap = timelib_is_leap(y-1);
- doy = timelib_day_of_year(y, m, d) + 1;
- if (y_leap && m > 2) {
- doy++;
- }
- jan1weekday = timelib_day_of_week(y, 1, 1);
- weekday = timelib_day_of_week(y, m, d);
- if (weekday == 0) weekday = 7;
- if (jan1weekday == 0) jan1weekday = 7;
- /* Find if Y M D falls in YearNumber Y-1, WeekNumber 52 or 53 */
- if (doy <= (8 - jan1weekday) && jan1weekday > 4) {
- *iy = y - 1;
- if (jan1weekday == 5 || (jan1weekday == 6 && prev_y_leap)) {
- *iw = 53;
- } else {
- *iw = 52;
- }
- } else {
- *iy = y;
- }
- /* 8. Find if Y M D falls in YearNumber Y+1, WeekNumber 1 */
- if (*iy == y) {
- int i;
- i = y_leap ? 366 : 365;
- if ((i - (doy - y_leap)) < (4 - weekday)) {
- *iy = y + 1;
- *iw = 1;
- return;
- }
- }
- /* 9. Find if Y M D falls in YearNumber Y, WeekNumber 1 through 53 */
- if (*iy == y) {
- int j;
- j = doy + (7 - weekday) + (jan1weekday - 1);
- *iw = j / 7;
- if (jan1weekday > 4) {
- *iw -= 1;
- }
- }
- }
- timelib_sll timelib_daynr_from_weeknr(timelib_sll y, timelib_sll w, timelib_sll d)
- {
- timelib_sll dow, day;
-
- /* Figure out the dayofweek for y-1-1 */
- dow = timelib_day_of_week(y, 1, 1);
- /* then use that to figure out the offset for day 1 of week 1 */
- day = 0 - (dow > 4 ? dow - 7 : dow);
- /* Add weeks and days */
- return day + ((w - 1) * 7) + d;
- }
- int timelib_valid_time(timelib_sll h, timelib_sll i, timelib_sll s)
- {
- if (h < 0 || h > 23 || i < 0 || i > 59 || s < 0 || s > 59) {
- return 0;
- }
- return 1;
- }
- int timelib_valid_date(timelib_sll y, timelib_sll m, timelib_sll d)
- {
- if (m < 1 || m > 12 || d < 1 || d > timelib_days_in_month(y, m)) {
- return 0;
- }
- return 1;
- }
- #if 0
- int main(void)
- {
- printf("dow = %d\n", timelib_day_of_week(1978, 12, 22)); /* 5 */
- printf("dow = %d\n", timelib_day_of_week(2005, 2, 19)); /* 6 */
- }
- #endif