(PHP 4 >= 4.1.0, PHP 5, PHP 7)

cal_days_in_monthDevolver el número de días de un mes para un año y un calendario dados


int cal_days_in_month ( int $calendar , int $month , int $year )

Esta función devolverá el número de días del mes month del año year para el calendario calendar especificado.



El calendario que se va a usar para el cálculo


El mes del calendario seleccionado


El año del calendario seleccionado

Valores devueltos

La longitud en días del mes seleccionado en el calendario dado.


Ejemplo #1 Ejemplo de cal_days_in_month()

cal_days_in_month(CAL_GREGORIAN82003); // 31
echo "Hubo {$número} días en agosto del 2003";

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User Contributed Notes 4 notes

brian at b5media dot com
10 years ago
Remember if you just want the days in the current month, use the date function:
$days = date("t");
dbindel at austin dot rr dot com
14 years ago
Here's a one-line function I just wrote to find the numbers of days in a month that doesn't depend on any other functions.

The reason I made this is because I just found out I forgot to compile PHP with support for calendars, and a class I'm writing for my website's open source section was broken. So rather than recompiling PHP (which I will get around to tomorrow I guess), I just wrote this function which should work just as well, and will always work without the requirement of PHP's calendar extension or any other PHP functions for that matter.

I learned the days of the month using the old knuckle & inbetween knuckle method, so that should explain the mod 7 part. :)

* days_in_month($month, $year)
* Returns the number of days in a given month and year, taking into account leap years.
* $month: numeric month (integers 1-12)
* $year: numeric year (any integer)
* Prec: $month is an integer between 1 and 12, inclusive, and $year is an integer.
* Post: none
// corrected by ben at sparkyb dot net
function days_in_month($month, $year)
// calculate number of days in a month
return $month == 2 ? ($year % 4 ? 28 : ($year % 100 ? 29 : ($year % 400 ? 28 : 29))) : (($month - 1) % 7 % 2 ? 30 : 31);

David Bindel
jeffbeall at comcast dot net
14 years ago
This will work great in future dates but will give the wrong answer for dates before 1550 (approx) when leap year was introduced and the calendar lost a year or two.
Sorry now to be more specific it has been a while sine I had to account for those later dates and had to take that into account but just a heads up for others to watch out.
geko45pj at yahoo dot com
10 years ago
# PHP Calendar (version 2.3), written by Keith Devens

function generate_calendar($year, $month, $days = array(), $day_name_length = 3, $month_href = NULL, $first_day = 0, $pn = array()){
$first_of_month = gmmktime(0,0,0,$month,1,$year);

#remember that mktime will automatically correct if invalid dates are entered
    # for instance, mktime(0,0,0,12,32,1997) will be the date for Jan 1, 1998
    # this provides a built in "rounding" feature to generate_calendar()

$day_names = array(); #generate all the day names according to the current locale
for($n=0,$t=(3+$first_day)*86400; $n<7; $n++,$t+=86400) #January 4, 1970 was a Sunday
$day_names[$n] = ucfirst(gmstrftime('%A',$t)); #%A means full textual day name

list($month, $year, $month_name, $weekday) = explode(',',gmstrftime('%m,%Y,%B,%w',$first_of_month));
$weekday = ($weekday + 7 - $first_day) % 7; #adjust for $first_day
$title   = htmlentities(ucfirst($month_name)).'&nbsp;'.$year#note that some locales don't capitalize month and day names

    #Begin calendar. Uses a real <caption>. See
@list($p, $pl) = each($pn); @list($n, $nl) = each($pn); #previous and next links, if applicable
if($p) $p = '<span class="calendar-prev">'.($pl ? '<a href="'.htmlspecialchars($pl).'">'.$p.'</a>' : $p).'</span>&nbsp;';
$n) $n = '&nbsp;<span class="calendar-next">'.($nl ? '<a href="'.htmlspecialchars($nl).'">'.$n.'</a>' : $n).'</span>';
$calendar = '<table class="calendar">'."\n".
'<caption class="calendar-month">'.$p.($month_href ? '<a href="'.htmlspecialchars($month_href).'">'.$title.'</a>' : $title).$n."</caption>\n<tr>";

$day_name_length){ #if the day names should be shown ($day_name_length > 0)
        #if day_name_length is >3, the full name of the day will be printed
foreach($day_names as $d)
$calendar .= '<th abbr="'.htmlentities($d).'">'.htmlentities($day_name_length < 4 ? substr($d,0,$day_name_length) : $d).'</th>';
$calendar .= "</tr>\n<tr>";

$weekday > 0) $calendar .= '<td colspan="'.$weekday.'">&nbsp;</td>'; #initial 'empty' days
for($day=1,$days_in_month=gmdate('t',$first_of_month); $day<=$days_in_month; $day++,$weekday++){
$weekday == 7){
$weekday   = 0; #start a new week
$calendar .= "</tr>\n<tr>";
$days[$day]) and is_array($days[$day])){
$link, $classes, $content) = $days[$day];
is_null($content))  $content  = $day;
$calendar .= '<td'.($classes ? ' class="'.htmlspecialchars($classes).'">' : '>').
$link ? '<a href="'.htmlspecialchars($link).'">'.$content.'</a>' : $content).'</td>';
$calendar .= "<td>$day</td>";
$weekday != 7) $calendar .= '<td colspan="'.(7-$weekday).'">&nbsp;</td>'; #remaining "empty" days

return $calendar."</tr>\n</table>\n";
generate_calendar(2010, 12, 16,3,NULL,0,15, $first_of_month, $day_names, $day_names[$n]);
#echo generate_calendar($year, $month, $days,$day_name_length,$month_href,$first_day,$pn);
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