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Digg  easter_date
Get Unix timestamp for midnight on Easter of a given year
(PHP 4, PHP 5)
Example 367. easter_date() example<?phpCode Examples / Notes » easter_dateray
The algorithm from BigTree will throw an error in 2021 and 2025. Better to install the PHP functions! Details here: http://aa.usno.navy.mil/faq/docs/easter.html phpuser
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; } ?> 14-aug-2006 03:46
I made the function like this ... works fine ! 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 $ostersonntag; } bigtree
A much smaller hack is the following. I ported this from a Delphi implementation of a function calculating easter dates. <?php function easter_date ($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 - ($C / 4) - ((8*$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; } ?> |
