How do I find what day the last saturday of the cu

This works for most months, but for example, April 2011 has 5 saturdays, so this returns 23 instead of 30.

$last_saturday = date("j", strtotime('Fourth Saturday'.date('F o')));

回答1:

last saturday seems to be interpreted as "previous saturday" in some constellations.

This is what works for me on PHP 5.3 on Windows 7: Jump to next month's first day, and look for last saturday.

 $nextMonthStart = mktime(0,0,0,date('m')+1,1,date('Y'));
 $last_saturday = date("d.m.Y",strtotime("previous saturday", $nextMonthStart));

works for me even in the edge case that the first day of next month is a saturday.

回答2:

Interestingly enough, strtotime("last saturday of this month") does exactly that.

See Supported Date and Time Formats for more, particularly the section on Relative Formats.

回答3:

These days people use strtotime too liberally... if you want to be real hardcore (and reinvent the wheel a bit) you can use this piece of code I wrote for Moodle back in the day, which I guess has some novelty value. I copied it from here.

The last Sunday of April 2011 is find_day_in_month(-1, 0, 4, 2011), which means "start searching from the last day of April 2011 backwards and tell me when the first Sunday you find is".

See it in action.

/**
 * Calculate the number of days in a given month
 *
 * @param int $month The month whose day count is sought
 * @param int $year The year of the month whose day count is sought
 * @return int
 */
function days_in_month($month, $year) {
   return intval(date('t', mktime(12, 0, 0, $month, 1, $year)));
}


/**
 * ?
 *
 * @todo Document what this function does
 * @param int $startday Defines the day from which to start searching (absolute value) and the direction in which to search (sign)
 * @param int $weekday -1 if you don't want the function to match a specific weekday; 0 to 6 to match specific weekdays
 * @param int $month The month wherein the day is sought
 * @param int $year The year wherein the day is sought
 * @return int
 */
function find_day_in_month($startday, $weekday, $month, $year) {
    $daysinmonth = days_in_month($month, $year);

    if($weekday == -1) {
        // Don't care about weekday, so return:
        //    abs($startday) if $startday != -1
        //    $daysinmonth otherwise
        return ($startday == -1) ? $daysinmonth : abs($startday);
    }

    // From now on we 're looking for a specific weekday

    // Give "end of month" its actual value, since we know it
    if($startday == -1) {
        $startday = -1 * $daysinmonth;
    }

    // Starting from day $startday, the sign is the direction

    if($startday < 1) {

        $startday = abs($startday);
        $lastmonthweekday  = strftime('%w', mktime(12, 0, 0, $month, $daysinmonth, $year));

        // This is the last such weekday of the month
        $lastinmonth = $daysinmonth + $weekday - $lastmonthweekday;
        if($lastinmonth > $daysinmonth) {
            $lastinmonth -= 7;
        }

        // Find the first such weekday <= $startday
        while($lastinmonth > $startday) {
            $lastinmonth -= 7;
        }

        return $lastinmonth;

    }
    else {

        $indexweekday = strftime('%w', mktime(12, 0, 0, $month, $startday, $year));

        $diff = $weekday - $indexweekday;
        if($diff < 0) {
            $diff += 7;
        }

        // This is the first such weekday of the month equal to or after $startday
        $firstfromindex = $startday + $diff;

        return $firstfromindex;

    }
}

回答4:

https://github.com/briannesbitt/carbon

<?php
require 'vendor/autoload.php';

use Carbon\Carbon;

$date = Carbon::now();
$date = $date->lastOfMonth(Carbon::SATURDAY);
echo 'last saturday = '.$date->day;

回答5:

$lastSaturDay= date('Y-m-d', strtotime('last saturday of this month'));