X. Calendar Functions

Введение

The calendar extension presents a series of functions to simplify converting between different calendar formats. The intermediary or standard it is based on is the Julian Day Count. The Julian Day Count is a count of days starting from January 1st, 4713 B.C. To convert between calendar systems, you must first convert to Julian Day Count, then to the calendar system of your choice. Julian Day Count is very different from the Julian Calendar! For more information on Julian Day Count, visit http://www.hermetic.ch/cal_stud/jdn.htm. For more information on calendar systems visit http://www.boogle.com/info/cal-overview.html. Excerpts from this page are included in these instructions, and are in quotes.

Установка

To get these functions to work, you have to compile PHP with --enable-calendar.

Версия PHP для Windows имеет встроенную поддержку данного расширения. Это означает, что для использования данных функций не требуется загрузка никаких дополнительных расширений.

Настройка во время выполнения

Данное расширение не определяет никакие директивы конфигурации в php.ini.

Типы ресурсов

Данное расширение не определяет никакие типы ресурсов.

Предопределенные константы

Перечисленные ниже константы определены данным расширением и могут быть доступны только в том случае, если PHP был собран с поддержкой этого расширения или же в том случае, если данное расширение подгружается во время выполнения.

CAL_GREGORIAN (integer)

CAL_JULIAN (integer)

CAL_JEWISH (integer)

CAL_FRENCH (integer)

CAL_NUM_CALS (integer)

CAL_DOW_DAYNO (integer)

CAL_DOW_SHORT (integer)

CAL_DOW_LONG (integer)

CAL_MONTH_GREGORIAN_SHORT (integer)

CAL_MONTH_GREGORIAN_LONG (integer)

CAL_MONTH_JULIAN_SHORT (integer)

CAL_MONTH_JULIAN_LONG (integer)

CAL_MONTH_JEWISH (integer)

CAL_MONTH_FRENCH (integer)

The following constants are available since PHP 4.3.0 :

CAL_EASTER_DEFAULT (integer)

CAL_EASTER_ROMAN (integer)

CAL_EASTER_ALWAYS_GREGORIAN (integer)

CAL_EASTER_ALWAYS_JULIAN (integer)

The following constants are available since PHP 5.0.0 :

CAL_JEWISH_ADD_ALAFIM_GERESH (integer)

CAL_JEWISH_ADD_ALAFIM (integer)

CAL_JEWISH_ADD_GERESHAYIM (integer)

Содержание
cal_days_in_month -- Return the number of days in a month for a given year and calendar
cal_from_jd -- Converts from Julian Day Count to a supported calendar
cal_info -- Returns information about a particular calendar
cal_to_jd -- Converts from a supported calendar to Julian Day Count
easter_date --  Get Unix timestamp for midnight on Easter of a given year
easter_days --  Get number of days after March 21 on which Easter falls for a given year
FrenchToJD --  Converts a date from the French Republican Calendar to a Julian Day Count
GregorianToJD --  Converts a Gregorian date to Julian Day Count
JDDayOfWeek -- Returns the day of the week
JDMonthName -- Returns a month name
JDToFrench --  Converts a Julian Day Count to the French Republican Calendar
JDToGregorian -- Converts Julian Day Count to Gregorian date
jdtojewish --  Converts a Julian day count to a Jewish calendar date
JDToJulian --  Converts a Julian Day Count to a Julian Calendar Date
jdtounix -- Convert Julian Day to Unix timestamp
JewishToJD --  Converts a date in the Jewish Calendar to Julian Day Count
JulianToJD --  Converts a Julian Calendar date to Julian Day Count
unixtojd -- Convert Unix timestamp to Julian Day


Calendar Functions
fRay Ferguson
21-Apr-2006 07:32
The following is a light reimplimentation of some of these functions wich can be used in an include file to work around the lack of --with-calendar in php implimentations.

<?php

/* IMPLEMENTS SUBSET OF PHP CALENDAR FUNCTIONS ON SYSTEMS COMPILED W/O --enable-calendar */

if (!function_exists('cal_days_in_month')){
       function cal_days_in_month($a_null, $a_month, $a_year) {
               return date('t', mktime(0, 0, 0, $a_month+1, 0, $a_year));
       }
}

if (!function_exists('cal_to_jd')){
       function cal_to_jd($a_null, $a_month, $a_day, $a_year){
               if ( $a_month <= 2 ){
                     $a_month = $a_month + 12 ;
                     $a_year = $a_year - 1 ;
               }
               $A = intval($a_year/100);
               $B = intval($A/4) ;
               $C = 2-$A+$B ;
               $E = intval(365.25*($a_year+4716)) ;
               $F = intval(30.6001*($a_month+1));
               return intval($C+$a_day+$E+$F-1524) ;
       }
}

if (!function_exists('get_jd_dmy')) {
   function get_jd_dmy($a_jd){
     $W = intval(($a_jd - 1867216.25)/36524.25) ;
     $X = intval($W/4) ;
     $A = $a_jd+1+$W-$X ;
     $B = $A+1524 ;
     $C = intval(($B-122.1)/365.25) ;
     $D = intval(365.25*$C) ;
     $E = intval(($B-$D)/30.6001) ;
     $F = intval(30.6001*$E) ;
     $a_day = $B-$D-$F ;
     if ( $E > 13 ) {
       $a_month=$E-13 ;
       $a_year = $C-4715 ;
     } else {
       $a_month=$E-1 ;
       $a_year=$C-4716 ;
     }
     return array($a_month, $a_day, $a_year) ;
   }
}

if (!function_exists('jdmonthname')) {
       function jdmonthname($a_jd,$a_mode){
               $tmp = get_jd_dmy($a_jd) ;
               $a_time = "$tmp[0]/$tmp[1]/$tmp[2]" ;
               switch($a_mode) {
                       case 0:
                               return strftime("%b",strtotime("$a_time")) ;
                       case 1:
                               return strftime("%B",strtotime("$a_time")) ;
               }
       }
}

if (!function_exists('jddayofweek')) {
       function jddayofweek($a_jd,$a_mode){
               $tmp = get_jd_dmy($a_jd) ;
               $a_time = "$tmp[0]/$tmp[1]/$tmp[2]" ;
               switch($a_mode) {
                       case 1:
                               return strftime("%A",strtotime("$a_time")) ;
                       case 2:
                               return strftime("%a",strtotime("$a_time")) ;
                       default:
                               return strftime("%w",strtotime("$a_time")) ;
               }
       }
}

?>
amichauer at gmx dot de
27-Jun-2005 09:46
<?php

class HijriCalendar
{
   function monthName($i) // $i = 1..12
   {
       static $month  = array(
           "Mxrrm", "Safar", "Rabig-l-wwl", "Rabig-l-Axr",
           "Cmd-l-wwl", "Cmd-l-Axr", "Racb", "bn",
           "Ramazan", "wl", "Z-l-Qd", "Z-l-Xicc"
       );
       return $month[$i-1];
   }

   function GregorianToHijri($time = null)
   {
       if ($time === null) $time = time();
       $m = date('m', $time);
       $d = date('d', $time);
       $y = date('Y', $time);

       return HijriCalendar::JDToHijri(
           cal_to_jd(CAL_GREGORIAN, $m, $d, $y));
   }

   function HijriToGregorian($m, $d, $y)
   {
       return jd_to_cal(CAL_GREGORIAN,
           HijriCalendar::HijriToJD($m, $d, $y));
   }

   # Julian Day Count To Hijri
   function JDToHijri($jd)
   {
       $jd = $jd - 1948440 + 10632;
       $n  = (int)(($jd - 1) / 10631);
       $jd = $jd - 10631 * $n + 354;
       $j  = ((int)((10985 - $jd) / 5316)) *
           ((int)(50 * $jd / 17719)) +
           ((int)($jd / 5670)) *
           ((int)(43 * $jd / 15238));
       $jd = $jd - ((int)((30 - $j) / 15)) *
           ((int)((17719 * $j) / 50)) -
           ((int)($j / 16)) *
           ((int)((15238 * $j) / 43)) + 29;
       $m  = (int)(24 * $jd / 709);
       $d  = $jd - (int)(709 * $m / 24);
       $y  = 30*$n + $j - 30;

       return array($m, $d, $y);
   }

   # Hijri To Julian Day Count
   function HijriToJD($m, $d, $y)
   {
       return (int)((11 * $y + 3) / 30) +
           354 * $y + 30 * $m -
           (int)(($m - 1) / 2) + $d + 1948440 - 385;
   }
};

$hijri = HijriCalendar::GregorianToHijri( time() );
echo $hijri[1].'. '.HijriCalendar::monthName($hijri[0]).' '.$hijri[2];

?>
pouya
03-Apr-2004 10:39
There is an implementation of the Persian calendar at www.farsiweb.info.
jthome at fcgov dot com
02-Oct-2003 11:38
Had a similar problem as curlee, except I needed to create a JDE_ERP date.  [format is CYYDDD]

<?php

function jde_date_create($month, $day, $year){
   /*
   *  NOTE: $month and $day CANNOT have leading zeroes,
   *        $year must be'YYYY' format
   */
   $jde_year_prefix = substr($year, 0, 1) - 1;
   $jde_year_suffix = substr($year, -2);
  
   //note that valid years for mktime are 1902-2037
   $timestamp = mktime(0,0,0,$month, $day, $year);
   $baseline_timestamp = mktime(0,0,0,1,0,$year);
  
   $day_count = round(($timestamp - $baseline_timestamp)/86400);
   $day_count_padded = str_pad($day_count,3,"0",STR_PAD_LEFT);

   return ($jde_year_prefix . $jde_year_suffix . $day_count_padded);
  
}

echo jde_date_create(6,25,2000);// will return '103176'

?>

--
Jim
curlee at mindspring dot com
29-Aug-2003 08:55
I solved a problem with Julian dates that are used in the JD Edwards ERP package (running on AS/400).  The Julian format for this system is as follows:  CYYDDD

Where C is 0 for 1900 and 1 for 2000
DDD is the day of the year count

I used the mktime built-in php function to convert dates to the normal DD/MM/YYYY format.  This function will convert dates that are between 1970 and 2038 (limitation of unix timestamps and the mktime function)

The $jde_date var needs to be a 6 len STRING.... if you use a numeric var type it will drop the leading 0 for any date that represents 1900.... this will botch the substr functions and thus make the whole thing wrong. 

function jde_date_conv($jde_date)
{

$ct = substr($jde_date,0,1);
$yr = substr($jde_date,1,2);
$dy = substr($jde_date,3,3);

if($ct == 0) $yr_pfx = 19;
if($ct == 1) $yr_pfx = 20;

$tlt_yr = $yr_pfx.$yr;

$base_time = mktime(0,0,0,1,0,$tlt_yr);

$unix_time = ($dy * 86400) + $base_time;

return date("m/d/Y" , $unix_time);
}
carlj at vibez dot ca
17-Jun-2003 12:28
Why not do something like this, to find the number of days in a month?

$monthNum = date("n"); // or any value from 1-12
$year        = date("Y"); // or any value >= 1
$numDays  = date("t",mktime(0,0,0,$monthNum,1,$year))

This will tell you if there is 28-31 days in a month
dy64 at dy64 dot de
12-Nov-2002 06:18
Best performance:
/*
 * Find the number of days in a month
 * Year is between 1 and 32767 inclusive
 * Month is between 1 and 12 inclusive
 */
function DayInMonth($month, $year) {
   var $daysInMonth = array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
   if ($month != 2) return $daysInMonth[$month - 1];
   return (checkdate($month, 29, $year)) ? 29 : 28;
}
kmcm at bigfoot dot com
20-Jan-2002 06:42
if, like me, you don't have a PHP build that includes the cal functions, you may want to use this function for sorting out leap year.

function days_in_feb($year){

   //$year must be YYYY
   //[gregorian] leap year math :
  
   if ($year < 0) $year++;
   $year += 4800;

   if ( ($year % 4) == 0) {
       if (($year % 100) == 0) {
           if (($year % 400) == 0) {
               return(29);
           } else {
               return(28);
           }
       } else {
           return(29);
       }
   } else {
       return(28);
   }
}

of course the next leap year isn't until the end of the century but this makes for timeless code I guess ...or if you are using 2000 in your dates or are going far back in time, etc, it is necessary.
mikebabcock at pobox dot com
17-Jul-2000 09:20
There are two world calculations for the date of Easter.  The Easter date function should account for this; one used (generally) by the Western world and one (generally) used by the Eastern (the official date used by the East Orthodox Church).
ssharma at odc dot net
31-Jan-2000 03:36
If you're interested in dates/calendars, check out the MCAL stuff.
manual/ref.mcal.php3

<bzwritecal_days_in_month>
 Last updated: Mon, 14 Nov 2005