easter_date

(PHP 4, PHP 5, PHP 7)

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

easter_days() - 得到指定年份的3月21日到复活节之间的天数 for calculating Easter before 1970 or after 2037

用户评论:

[#1] adwil at live dot com [2014-04-10 15:01:22]

Hey, recently I needed a function to get realization dates in online shop, so here it is (ready to go for polish users, please adjust your dates for any other country):

<?php function getWorkday($date1,$workDays) { $workDays = (int)$workDays; if ($workDays <= 0) return null; $date1=strtotime('-1 day',strtotime($date1)); $lastYear = null; $hol=array('01-01','01-06','05-01','05-03','08-15','11-01','11-11','12-25','12-26'); //array of month-date of static holidays (these are from Poland) $i = 0; while ($i<=$workDays) { $year = date('Y', $date1); if ($year !== $lastYear){ $lastYear = $year; $easter = date('m-d', easter_date($year)); $date = strtotime($year . '-' . $easter); // easter $easterSec = date('m-d', strtotime('+1 day', $date)); // easter monday $greens = date('m-d', strtotime('+49 days', $date)); // zielone swiatki $cc = date('m-d', strtotime('+60 days', $date)); // boze cialo $hol[] = $easter; $hol[] = $easterSec; $hol[] = $greens; $hol[] = $cc; } $weekDay=date('w',$date1); if (!($weekDay==0 || $weekDay==6 || in_array(date('m-d',$date1),$hol))) $i++; $date1=strtotime('+1 day',$date1); } return date('Y-m-d',$date1); } ?>

[#2] Guillaume Dufrene [2013-03-30 08:13:56]

I found a problem with holidays timestamp computation and daylight saving time.
An article about it at http://goo.gl/76t31 (in french only, sorry).

In summary, this year (2013) easter begins before adding an hour for daylight saving time (occured sunday at 3:00). It means that if you do $easter + X, where x is a number of seconds equivalent to one day, 39 days or 50 days, the result is not equals to a midnight timestamp...

Here a function to check if a midnight timestamp is equals to an holiday :

function isHoliday( $ts ) {
// Licence : Creative Commons (BY)
// By Webpulser - http://goo.gl/76t31
  $fixed_holidays = array( ??01-01??, ??01-05??, ??08-05??, ??14-07??, ??15-08??, ??11-11??, ??25-12?? );
  $format = ??d-m??;

$dm = date($format, $ts);
  if ( in_array($dm, $fixed_holidays) ) return true;

$easter = easter_date( date(??Y??, $ts) );
  if ( date($format, $easter +   86400) == $dm ) return true;
  if ( date($format, $easter + 3369600) == $dm ) return true;
  if ( date($format, $easter + 4320000) == $dm ) return true;

return false;
}

feel free to use / modify.

[#3] luca at musician dot org [2012-05-03 15:19:01]

Due to range limitations of core functions such as easter_date(), mktime(), strtotime(), I wrote this function to get the Easter Day in string format yyyy-mm-dd.

function myEaster($year)
{

     //The next line would do the work if there were no limitations:
    //return date("Y-m-d",easter_date($year));


    $march21=date("$year-03-21");
    $days=easter_days($year);
    if($year<=2037)
    //The next line would do the work if strtotime() wasn't affected by same limitations. But, the if..else is required to handle all years.
        $date = date("Y-m-d",strtotime(date("Y-m-d", strtotime($march21)) . " +$days day"));
    else
    {
        if($days<=10){
            $day=str_pad(21+$days, 2, '0', STR_PAD_LEFT);
            $date=date("$year-03-$day");
        }
        else
        {
            $day=str_pad($days-10, 2, '0', STR_PAD_LEFT);
            $date=date("$year-04-$day");
        }
    }

    return $date;
}

[#4] py dot lebecq at gmail dot com [2010-03-11 07:44:45]

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 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), // F??te du travail mktime(0, 0, 0, 5, 8, $year), // Victoire des alli??s mktime(0, 0, 0, 7, 14, $year), // F??te 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; } ?>

[#5] peter dot burden at gmail dot com [2010-01-28 16:55:34]

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 ?>

[#6] maxie [2008-06-12 01:36:46]

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; } ?>

[#7] nigelf at esp dot co dot uk [2008-01-28 03:50:23]

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.

[#8] [2006-08-14 07:46:15]

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; } ?>

[#9] phpuser [2004-11-08 08:17:16]

The algorithm from Bigtree is correct if you add some (int) cast
<?php function easter_date ($Year) { $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; } ?>