cal_days_in_month

(PHP 4 >= 4.1.0, PHP 5)

cal_days_in_month -- Return the number of days in a month for a given year and calendar

Description

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

This function will return the number of days in the month of year for the specified calendar.

例 1. cal_days_in_month() example

<?php
$num
= cal_days_in_month(CAL_GREGORIAN, 8, 2003); // 31
echo "There was $num days in August 2003";
?>

See also jdtounix().


add a note add a note User Contributed Notes
geko45pj at yahoo dot com
19-Jul-2007 06:28
<?php
# 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 http://diveintomark.org/archives/2002/07/03
  
@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;';
   if(
$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>";

   if(
$day_name_length){ #if the day names should be shown ($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>";
   }

   if(
$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++){
       if(
$weekday == 7){
          
$weekday  = 0; #start a new week
          
$calendar .= "</tr>\n<tr>";
       }
       if(isset(
$days[$day]) and is_array($days[$day])){
           @list(
$link, $classes, $content) = $days[$day];
           if(
is_null($content))  $content  = $day;
          
$calendar .= '<td'.($classes ? ' class="'.htmlspecialchars($classes).'">' : '>').
               (
$link ? '<a href="'.htmlspecialchars($link).'">'.$content.'</a>' : $content).'</td>';
       }
       else
$calendar .= "<td>$day</td>";
   }
   if(
$weekday != 7) $calendar .= '<td colspan="'.(7-$weekday).'">&nbsp;</td>'; #remaining "empty" days

  
return $calendar."</tr>\n</table>\n";
}
echo
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,$pn);
?>
sasha at alronix dot com
05-Apr-2006 01:46
function days_in_month($a_month, $a_year) {
   return date('t', strtotime($a_year . '-' . $a_month . '-01'));
}
NiGhMa
23-May-2005 08:00
Stay simple ;)

$ndays = date("t"); //return the number of days for this month and this year

$ndays = date("t", mktime(0, 0, 0, 12, 1, 2004)); // You can also specify a date

c u
Pasci - webmaster at cyber-style dot net
07-Jan-2005 10:21
Here's the one line solution without loops or other slow stuff ;)

<?php

$daynum
= date("j",mktime(0,0,0,$month+1,0,$year));

?>
paul (at) bughunt3r.com
18-Apr-2004 03:31
Here is a nifty function to return the date for easter for ranges beyond 2037 or before 1970.

<?php
  
function str_easter_date ($year) {
      
$days = easter_days ($year);
      
$days_in_march = cal_days_in_month (CAL_GREGORIAN, 3, $year);
       if ((
$days + 21) < $days_in_march) {
          
$month = "March";
          
$date = $days + 21;
       } else {
          
$month = "April";
          
$date = ($days + 21) - $days_in_march;
       }
      
       return
"$month $date, $year";
   }
?>
jeffbeall at comcast dot net
14-Apr-2004 05:04
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.
dbindel at austin dot rr dot com
02-Jan-2004 05:06
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. :)

<?php
/*
 * 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);
}
?>

Enjoy,
David Bindel