FrenchToJD
Some people might find it useful to use a function that takes in dates formatted by ISO8601 standards (yyyy-mm-dd):
<?php function daysBetweenDate($from, $till) {
/*
*This function will calculate the difference between two given dates.
*
*Please input time by ISO 8601 standards (yyyy-mm-dd).
*i.e: daysBetweenDate('2009-01-01', '2010-01-01');
*This will return 365.
*
*Author: brian [at] slaapkop [dot] net
*May 5th 2010
*/
if($till < $from) {
trigger_error("The date till is before the date from", E_USER_NOTICE);
}
//Explode date since gregoriantojd() requires mm, dd, yyyy input;
$from = explode('-', $from);
$till = explode('-', $till);
//Calculate date to Julian Day Count with freshly created array $from.
$from = gregoriantojd($from[1], $from[2], $from[0])."<br />";
//Calculate date to Julian Day Count with freshly created array $till.
$till = gregoriantojd($till[1], $till[2], $till[0])."<br />";
//Substract the days $till (largest number) from $from (smallest number) to get the amount of days
$days = ($till - $from);
//Return the number of days.
return $days;
//Isn't it sad how my comments use more lines than the actual code?
}
?>
GregorianToJD
(PHP 4, PHP 5)
GregorianToJD — Convertit une date grégorienne en nombre de jours du calendrier Julien
Description
int gregoriantojd
( int
$month
, int $day
, int $year
)Intervalle de validité pour le calendrier grégorien : 4714 avant JC à 9999 après JC.A.D.
Bien qu'il soit possible de manipuler des dates jusqu'en 4714 avant JC, une telle utilisation n'est pas significative. En effet, ce calendrier fut créé le 18 octobre 1582 après J.C. (ou 5 octobre 1582 en calendrier grec). Certains pays ne l'acceptèrent que bien plus tard. Par exemple, les britanniques n'y passèrent qu'en 1752, les Russes en 1918 et les Grecs en 1923. La plupart des pays européens utilisaient le calendrier Julien avant le Grégorien.
Liste de paramètres
-
month -
Le mois, sous la forme d'un nombre compris entre 1 (pour Janvier) et 12 (pour Décembre)
-
day -
Le jour, sous la forme d'un nombre compris entre 1 et 31
-
year -
L'année, sous la forme d'un nombre compris entre -4714 et 9999
Valeurs de retour
Le jour Julien pour la date fournie du calendrier Grégorien, sous la forme d'un entier.
Exemples
Exemple #1 Fonctions calendrier
<?php
$jd = GregorianToJD(10, 11, 1970);
echo "$jd\n";
$gregorian = JDToGregorian($jd);
echo "$gregorian\n";
?>
Voir aussi
- jdtogregorian() - Convertit le nombre de jours du calendrier Julien en date grégorienne
- cal_to_jd() - Convertit un calendrier en nombre de jours Julien
add a note
User Contributed Notes
GregorianToJD
brian at slaapkop dot net
10-May-2010 07:53
jfg
07-Apr-2009 01:19
If you need the same output as the g_date_get_julian function of the GlibC, here is my php implementation :
<?php
/**
* Glib g_date_get_julian PHP implementation
*
* @param $str Date string in a format accepted by strtotime
* @author jfg
*/
private function _get_julian( $str )
{
$d = date_create($str);
if( $d == false )
return 0;
$day_in_year = (int) date_format($d, "z");
$year = (int) date_format($d, "Y") - 1;
$julian_days = $year * 365;
$julian_days += ($year >>= 2);
$julian_days -= ($year /= 25);
$julian_days += $year >> 2;
$julian_days += $day_in_year + 1;
return ceil($julian_days);
}
?>
ryker at ridgex dot net
06-Jun-2006 08:27
<?php
/*
* ComputeDateDifference(...)
* Description:
* Calculates the difference between two dates.
*
* Parameter:
* $m0, $d0, $y0 => 1. Moth/Day/Year
* $m1, $d1, $y1 => 2. Moth/Day/Year
*
* Return:
* Difference between given dates in days.
*
* Autor:
* 06.06.2006 - Christian Meyer <ryker@ridgex.net>
*/
function ComputeDateDifference($m0,$d0,$y0,$m1,$d1,$y1)
{
$x0 = gregoriantojd($m0,$d0,$y0);
$x1 = gregoriantojd($m1,$d1,$y1);
$diff = $x1 - $x0;
if ($diff < 0)
$diff *= -1; // abs
return $diff;
}
?>
jettyrat at jettyfishing dot com
17-Mar-2005 01:34
You can obtain the decimal fraction of the Julian date with the php gregoriantojd() function or the function shown below by applying this code to the returned value.
<?php
$julianDate = gregoriantojd($month, $day, $year);
//correct for half-day offset
$dayfrac = date('G') / 24 - .5;
if ($dayfrac < 0) $dayfrac += 1;
//now set the fraction of a day
$frac = $dayfrac + (date('i') + date('s') / 60) / 60 / 24;
$julianDate = $julianDate + $frac;
?>
httpwebwitch
08-Jun-2004 04:04
This function also ignores decimal fractions in JD dates, and it uses non-standard format for returning the Gregorian date.
So, if your JD date is 2453056.28673, the Gregorian returned value is 2/20/2004, not "2004-02-20 23:45:36"
The decimal part is important, since the Julian day begins at noon, for example 2453056.49 is on Friday, 2453056.50 is on Saturday. Discarding the decimal part means that your returned Gregorian Date will be wrong 50% of the time.