Calendar 函数
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cal_days_in_month

(PHP 4 >= 4.1.0, PHP 5)

cal_days_in_month — 返回某个历法中某年中某月的天数

说明

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

该函数返回特定历法中的某年中的某月的天数。

参数

calendar

用来计算的某个历法

month

选定历法中的某月

year

选定历法中的某年

返回值

指定历法中选定的某月的天数。

范例

Example #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";
?>

Calendar 函数
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PHP手册 - N: 返回某个历法中某年中某月的天数

用户评论:

Anonymous (11-Nov-2011 11:51)

You can also use the date() function to get the number of days in a month. You can also pass the 2nd param strtotime() and specify a specific date:

date('t');

adam.pippin at ohmedia.ca (14-Jun-2011 11:06)

Forgot to compile the calendar plugin in... Wrote a workaround while I waited for it to compile. It only supports the Gregorian calendar.

<?php
if (!function_exists('cal_days_in_month'))
{
    function cal_days_in_month($calendar, $month, $year)
    {
        return date('t', mktime(0, 0, 0, $month, 1, $year));
    }
}
if (!defined('CAL_GREGORIAN'))
    define('CAL_GREGORIAN', 1);
?>

deva dot ananth at gmail dot com (10-Mar-2011 01:44)

Function  for calculation number of days until birthday:

<?php
function daysLeftForBirthday($devabirthdate)
{
    /* input birthday date format -> Y-m-d */
    list($y, $m, $d) = explode('-',$devabirthdate);
    $nowdate = mktime(0, 0, 0, date("m"), date("d"), date("Y"));
    $nextbirthday = mktime(0,0,0,$m, $d, date("Y"));

    if ($nextbirthday<$nowdate)
        $nextbirthday=$nextbirthday+(60*60*24*365);

    $daycount=intval(($nextbirthday-$nowdate)/(60*60*24));

    return $daycount;
}
?>

brian at b5media dot com (05-Dec-2007 12:55)

Remember if you just want the days in the current month, use the date function:
$days = date("t");

geko45pj at yahoo dot com (19-Jul-2007 07:28)

<?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);
?>

paul (at) bughunt3r.com (18-Apr-2004 04:31)

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 06:04)

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