(PHP 4, PHP 5)
jdtogregorian — Konvertierung vom Julianischen Datum zum Gregorianischen Kalender
Diese Funktion konvertiert den in julianday angegebenen Tag im Julianischen Datum in einen String, der das Datum nach dem Gregorianischen Kalender in der Form "MM/DD/YYYY" enthält.
Ein Julianischer Tag als Integer
Ein Gregorianisches Datum als String der Form "Monat/Tag/Jahr"
The php gregoriantojd() and jdtogregorian() functions, in addition to the limitations noted by httpwebwitch, does not take account of the 'Astronomical' system of reckoning - i.e. using a year zero, instead of going directly from 1BCE to 1CE, as with the Christian Anno Domini system.
These functions can be used to wrap the php built-ins to return ISO 8601 compliant dates:
<?php
function ISO8601toJD($ceDate) {
list($day, $month, $year) = array_map('strrev',explode('-', strrev($ceDate), 3));
if ($year <= 0) $year--;
return gregoriantojd($month, $day, $year);
}
function JDtoISO8601($JD) {
if ($JD <= 1721425) $JD += 365;
list($month, $day, $year) = explode('/', jdtogregorian($JD));
return sprintf('%+05d-%02d-%02d', $year, $month, $day);
}
?>
<?php
// original script:
// http://www.codeproject.com/datetime/exceldmy.asp
// Excel/Lotus 123 have a bug with 29-02-1900.
// 1900 is not a leap year, but Excel/Lotus 123 think it is...
function excel_D2DMY($days) {
if ($days <1) return "";
if ($days == 60) {
return array('day'=>29,'month'=>2,'year'=>1900);
} else {
if ($days < 60) {
// Because of the 29-02-1900 bug, any serial date
// under 60 is one off... Compensate.
++$days;
}
// Modified Julian to DMY calculation with an addition of 2415019
$l = $days + 68569 + 2415019;
$n = floor(( 4 * $l ) / 146097);
$l = $l - floor(( 146097 * $n + 3 ) / 4);
$i = floor(( 4000 * ( $l + 1 ) ) / 1461001);
$l = $l - floor(( 1461 * $i ) / 4) + 31;
$j = floor(( 80 * $l ) / 2447);
$nDay = $l - floor(( 2447 * $j ) / 80);
$l = floor($j / 11);
$nMonth = $j + 2 - ( 12 * $l );
$nYear = 100 * ( $n - 49 ) + $i + $l;
$ret = array('day'=>$nDay,'month'=>$nMonth,'year'=>$nYear);
return $ret;
}
}
/**
* @desc Returns Excel serialDate constant calculated from gregorian date
* original javascript found @ http://wwwmacho.mcmaster.ca/JAVA/JD.html
* ported to PHP by XL:-)
*
* tested compatibility with EXCEL dates between 01/01/1900..31.12.2099,
* year given eventually as 0 (=1900)..199 (=2099)
* adds also days if supplied argument more than real number of days
* in particular month (same applies to months)
* as for years bellow 1900: algorhytm is not exact, therefore limitation
* for years 1900 - 2099
*/
function excel_DMY2D($d, $m, $y, $uh=0, $um=0, $us=0) {
if($y<1900){
if($y<0 || $y>199){
echo ' !!! Invalid year ['.$y.'], must be between 1900 - 2099 or 0 - 199 !!!';
return false;
}else{
$y += 1900;
}
}
$extra = 100.0*$y + $m - 190002.5;
$rjd = 367.0*$y;
$rjd -= floor(7.0*($y+floor(($m+9.0)/12.0))/4.0);
$rjd += floor(275.0*$m/9.0);
$rjd += $d;
$rjd += ($uh + ($um + $us/60.0)/60.)/24.0;
$rjd += 1721013.5;
$rjd -= 0.5*$extra/abs($extra);
$rjd += 0.5;
$rjd -= 2415020.5; // JD correction constant for 01/01/1900
$rjd += ($rjd>60) ? 2 : 1; // adjust to inheritet EXCEL/LOTUS bug
return $rjd;
}
?>
I have changed treebe's function a bit:
<?php
function jd_to_greg($julian) {
$julian = $julian - 1721119;
$calc1 = 4 * $julian - 1;
$year = floor($calc1 / 146097);
$julian = floor($calc1 - 146097 * $year);
$day = floor($julian / 4);
$calc2 = 4 * $day + 3;
$julian = floor($calc2 / 1461);
$day = $calc2 - 1461 * $julian;
$day = floor(($day + 4) / 4);
$calc3 = 5 * $day - 3;
$month = floor($calc3 / 153);
$day = $calc3 - 153 * $month;
$day = floor(($day + 5) / 5);
$year = 100 * $year + $julian;
if ($month < 10) {
$month = $month + 3;
}
else {
$month = $month - 9;
$year = $year + 1;
}
if ($day < 10) {
$day = "0".$day;
}
if ($month < 10) {
$month = "0".$month;
}
return $day."/".$month."/".$year;
}
?>
So, if the in the old format the 1st January 2005 was "1.1.2005", now the function will return "01/01/2005". I hope it could be useful to someone :)
JD days may have decimal fractions which correspond to the time of day. The Julian day begins at noon, and the decimal fraction measures fractional days until the beginning of the next day at noon.
For instance, Julian Day 2453179.00000 is June 22, 2004, at 12:00pm (noon).
One hour later, it's 2453179.04167
At 2453179.20833 I'll have dinner, and
at 2453179.45833, it's time for the evening news.
After a good night of sleep, my alarm will go off at 2453179.83333,
then at noon on June 23, a new Julian Day begins at 2453180.
To use these functions with fractional days, strip the fractional part with floor(), and apply the function to the integer part.
Then add 12 hours, bringing you to noon of that day. That is the actual time returned by JDToGregorian().
Then add the fractional part of the day, by multiplying the decimal part of the Julian Day by (24*60*60) seconds. This may take you forward or backward to a different Gregorian calendar date.
I have made a slight modification to treebe's jd to greg function, this one will transform a unix timestamp to Gregorian day/month/year format...
<?php
function unix_to_greg($unix_timestamp) {
$julian = floor(((($unix_timestamp / "60") / "60") / "24") + "2440588");
$julian = $julian - 1721119;
$calc1 = 4 * $julian - 1;
$year = floor($calc1 / 146097);
$julian = floor($calc1 - 146097 * $year);
$day = floor($julian / 4);
$calc2 = 4 * $day + 3;
$julian = floor($calc2 / 1461);
$day = $calc2 - 1461 * $julian;
$day = floor(($day + 4) / 4);
$calc3 = 5 * $day - 3;
$month = floor($calc3 / 153);
$day = $calc3 - 153 * $month;
$day = floor(($day + 5) / 5);
$year = 100 * $year + $julian;
if ($month < 10)
{
$month = $month + 3;
}else{
$month = $month - 9;
$year = $year + 1;
}
return "$day.$month.$year";
}
?>
Julian to Gregorian date change.
If you do not have the calendar extensions loaded this is little function works realy well.
<?php
function jd_to_greg($julian) {
$julian = $julian - 1721119;
$calc1 = 4 * $julian - 1;
$year = floor($calc1 / 146097);
$julian = floor($calc1 - 146097 * $year);
$day = floor($julian / 4);
$calc2 = 4 * $day + 3;
$julian = floor($calc2 / 1461);
$day = $calc2 - 1461 * $julian;
$day = floor(($day + 4) / 4);
$calc3 = 5 * $day - 3;
$month = floor($calc3 / 153);
$day = $calc3 - 153 * $month;
$day = floor(($day + 5) / 5);
$year = 100 * $year + $julian;
if ($month < 10) {
$month = $month + 3;
}
else {
$month = $month - 9;
$year = $year + 1;
}
return "$day.$month.$year";
}
?>