Calendar 函数
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easter_date

(PHP 4, PHP 5)

easter_date — 得到指定年份的复活节午夜时的Unix时间戳。

说明

int easter_date ([ int $year ] )

返回指定年份的复活节午夜时的Unix时间戳。

Warning

如果给定的年份超出Unix时间戳的范围（比如1970年以前或2037年以后），该函数将返回一个警告。

复活节的日期是由尼西亚议会在AD325年确定的为每年春分月圆后的第一个星期日。春分一般是在3月21日，这就简化为只要计算满月的日期和紧挨的星期日的日期。这里所用的算法是在532年由Dionysius Exiguus所介绍的，参考了Julian历法和Gregorian历法这两个历法来提高精确度。（在1753年以前用Julian历法计算，该历法是一个以19年为周期来确定月亮的相位的历法。在1753年以后用Gregorian历法计算，该历法由Clavius和Lilius发明，由Pope Gregory 8世在1582年推广）

参数

year

1970年至2037年之间的数字形式的年份。

返回值

复活节日期的Unix时间戳。

更新日志

版本 说明
Since 4.3.0 year参数可选，缺省的默认值是当年。

范例

Example #1 easter_date() example

<?php

echo date("M-d-Y", easter_date(1999));        // Apr-04-1999
echo date("M-d-Y", easter_date(2000));        // Apr-23-2000
echo date("M-d-Y", easter_date(2001));        // Apr-15-2001

?>

参见

Calendar 函数
在线手册：中文 英文
PHP手册
PHP手册 - N: 得到指定年份的复活节午夜时的Unix时间戳。

用户评论:

py dot lebecq at gmail dot com (11-Mar-2010 03:44)

I recently had to write a function that allows me to know if today is a holiday.

And in France, we have some holidays which depends on the easter date. Maybe this will be helpful to someone.

Just modify in the $holidays array the actual holidays dates of your country.

<?php
/**
 * This function returns an array of timestamp corresponding to french holidays
 */
protected static function getHolidays($year = null)
{
  if ($year === null)
  {
    $year = intval(date('Y'));
  }
   
  $easterDate  = easter_date($year);
  $easterDay   = date('j', $easterDate);
  $easterMonth = date('n', $easterDate);
  $easterYear   = date('Y', $easterDate);

  $holidays = array(
    // These days have a fixed date
    mktime(0, 0, 0, 1,  1,  $year),  // 1er janvier
    mktime(0, 0, 0, 5,  1,  $year),  // Fête du travail
    mktime(0, 0, 0, 5,  8,  $year),  // Victoire des alliés
    mktime(0, 0, 0, 7,  14, $year),  // Fête nationale
    mktime(0, 0, 0, 8,  15, $year),  // Assomption
    mktime(0, 0, 0, 11, 1,  $year),  // Toussaint
    mktime(0, 0, 0, 11, 11, $year),  // Armistice
    mktime(0, 0, 0, 12, 25, $year),  // Noel

    // These days have a date depending on easter
    mktime(0, 0, 0, $easterMonth, $easterDay + 2,  $easterYear),
    mktime(0, 0, 0, $easterMonth, $easterDay + 40, $easterYear),
    mktime(0, 0, 0, $easterMonth, $easterDay + 50, $easterYear),
  );

  sort($holidays);
 
  return $holidays;
}
?>

peter dot burden at gmail dot com (29-Jan-2010 12:55)

In 5.3.1 easter_date() returns GMT of start of Easter Day in UK allowing
for UK Summer Time. If you are in another time zone you need to
calculate offsets.
<?php
        $e1 = easter_date(2008);
        $e2 = easter_date(2009);
        echo "Timestamps " . $e1 . " " . $e2 . "\n";

        //      Timestamps 1206230400 1239490800

        echo "Days between Easter 2008 Easter 2009 = " . ($e2-$e1)/86400 . "\n";

        //      Days between Easter 2008 Easter 2009 = 384.958333333 - i.e. 384 days 23 hours

        date_default_timezone_set("Europe/London");
        echo date( " l, jS F Y H:i TO",$e1) . "\n";
        echo date( " l, jS F Y H:i TO",$e2) . "\n";

        //      Sunday, 23rd March 2008 00:00 GMT+0000
        //      Sunday, 12th April 2009 00:00 BST+0100

        date_default_timezone_set("America/New_York");
        echo date( " l, jS F Y H:i TO",$e1) . "\n";
        echo date( " l, jS F Y H:i TO",$e2) . "\n";

        //      Saturday, 22nd March 2008 20:00 EDT-0400
        //      Saturday, 11th April 2009 19:00 EDT-0400
        //      Daylight saving time in effect - New York 4 hours behind GMT
?>

maxie (12-Jun-2008 09:36)

To compute the correct Easter date for Eastern Orthodox Churches I made a function based on the Meeus Julian algorithm:

<?php
function orthodox_eastern($year) {
    $a = $year % 4;
    $b = $year % 7;
    $c = $year % 19;
    $d = (19 * $c + 15) % 30;
    $e = (2 * $a + 4 * $b - $d + 34) % 7;
    $month = floor(($d + $e + 114) / 31);
    $day = (($d + $e + 114) % 31) + 1;
   
    $de = mktime(0, 0, 0, $month, $day + 13, $year);
   
    return $de;
}
?>

nigelf at esp dot co dot uk (28-Jan-2008 11:50)

v5.2.1 - There is a known bug with easter_date() that can return incorrect dates for some years:

<?php
// 2008 OK
echo date("D d M Y", easter_date(2008));  // Sun 23 Mar 2008

// 2009 returns Saturday
echo date("D d M Y", easter_date(2009));  // Sat 11 Apr 2009
?>


However easter_days() works correctly:

<?php
echo date("D d M Y", strtotime("2009-03-21 +".easter_days(2009)." days"));  // Sun 12 Apr 2009
?>

It is apparently related to timezone settings.

(14-Aug-2006 03:46)

I made the function like this ... works fine !

<?php
function ostern
{
    $maerz21=date('z',mktime(0,0,0,3,21,$jb));

    $d=((15 + $jb/100 - $jb/400 - (8 * $jb/100 + 13) / 25)%30 + 19 * ($jb%19))%30;

    if ($d==29)
    {
        $D=28;
    }
    elseif($d==28 && ($jb%17)>=11)
    {
        $D=27;
    }
    else $D=$d;   

    $e=(2 * ($jb%4) + 4 *($jb%7) + 6 * $D + (6 + $jb/100 - $jb/400 - 2)%7)%7;

    $ostersonntag=$e+$D+1+$maerz21;
    return $ostersonntag;
}
?>

phpuser (08-Nov-2004 04:17)

The algorithm from Bigtree is correct if you add some (int) cast
<?php
   function easter_date ($Year) {
  
       /*
       G is the Golden Number-1
       H is 23-Epact (modulo 30)
       I is the number of days from 21 March to the Paschal full moon
       J is the weekday for the Paschal full moon (0=Sunday,
         1=Monday, etc.)
       L is the number of days from 21 March to the Sunday on or before
         the Paschal full moon (a number between -6 and 28)
       */
      

         $G = $Year % 19;
         $C = (int)($Year / 100);
         $H = (int)($C - (int)($C / 4) - (int)((8*$C+13) / 25) + 19*$G + 15) % 30;
         $I = (int)$H - (int)($H / 28)*(1 - (int)($H / 28)*(int)(29 / ($H + 1))*((int)(21 - $G) / 11));
         $J = ($Year + (int)($Year/4) + $I + 2 - $C + (int)($C/4)) % 7;
         $L = $I - $J;
         $m = 3 + (int)(($L + 40) / 44);
         $d = $L + 28 - 31 * ((int)($m / 4));
         $y = $Year;
         $E = mktime(0,0,0, $m, $d, $y);

         return $E;

   }
?>