CODEWITHSUNDEEP
phpmysql
user520300
user520300

Reputation: 1527

php or mysql list dates between range?

I need to generate a list of dates (with either php or mysql or both) where i have a start and end date specified? For example if the start date is 2012-03-31 and the end date is 2012-04-05 how can i generate a list like this?

2012-03-31
2012-04-01
2012-04-02
2012-04-03
2012-04-04
2012-04-05

I have a mysql table with a start and end date but i need the full list of dates.

Upvotes: 0

Views: 703

Answers (4)

dkellner
dkellner

Reputation: 9926

Super fast version

Date conversions are costly. I was disappointed by the performance so I tried to tune it a little for speed. It's more like a case study for optimization, but I'm going to leave it here because it's almost 3x faster than usual. It works by reducing the number of times date( ) being called.

function listDaysBetween($from,$till) {

    if($till<$from) return[];            //  handle the obvious empty case

    $tsFrom = strtotime("$from 11:00");  //  middle of first day
    $tsTill = strtotime("$till 11:00");  //  middle of last day
    $tsDiff = $tsTill - $tsFrom;         //  seconds diff
    $diff = round($tsDiff/86400);        //  days diff; output length
    $ts = $tsFrom;                       //  $ts will follow us along
    $day = $from;                        //  $day will scan the range
    $days = [$day];                      //  put the first one in there

    while($diff-->0) {                   //  a disguised for-loop
        $ts+=86400;                      //  keep timestamp following
        $d = (int)($day[8].$day[9]);     //  get the day part (fast)

        if($d>27) {                      //  at the end of each month,
            $day = date("Y-m-d",$ts);    //  it's better to ask date()
        }else{                           //  otherwise we do it faster
            $d+=101; $d="$d";            //  zero-padding to 2 digits
            $day[8] = $d[1];             //  direct character replace
            $day[9] = $d[2];             //  is faster than substr()
        }
        $days[] = $day;                  //  build output array
    }

    return $days;
}

I hope you'll enjoy the nasty tricks. Tried many ways for many parts of this code, this version is a clear winner so far but I'm open for suggestions. (Apart from caching in a static variable for subsequent calls. That's cheating. I'd totally do it but still.)

Read more about this if you like.

NOTE: this function has no input control, you'll need at least some regex to avoid accidental endless loops when calling with bogus data. I omitted those lines for brevity.

Upvotes: 0

Jon Gauthier
Jon Gauthier

Reputation: 25572

Using PHP's DateTime library:

<?php

$start_str = '2012-03-31';
$end_str = '2012-04-05';

$start = new DateTime($start_str);
$end = new DateTime($end_str . ' +1 day'); // note that the end date is excluded from a DatePeriod

foreach (new DatePeriod($start, new DateInterval('P1D'), $end) as $day) {
        echo $day->format('Y-m-d'), "\n";
}

Source

Upvotes: 1

Michael
Michael

Reputation: 12806

Try this:

<?php

  // Set the start and current date
  $start = $date = '2012-03-31';

  // Set the end date
  $end = '2012-04-05';

  // Set the initial increment value
  $i = 0;

  // The array to store the dates
  $dates = array();

  // While the current date is not the end, and while the start is not later than the end, add the next day to the array    
  while ($date != $end && $start <= $end)
  {
    $dates[] = $date = date('Y-m-d', strtotime($start . ' + ' . $i++ . ' day'));
  }

  // Output the list of dates
  print_r($dates);

Upvotes: 0

Jon Cairns
Jon Cairns

Reputation: 11951

Something like this should do it:

//Get start date and end date from database

$start_time = strtotime($start_date);
$end_time = strtotime($end_date);
$date_list = array($start_date);

$current_time = $start_time;

while($current_time < $end_time) {
    //Add one day
    $current_time += 86400;
    $date_list[] = date('Y-m-d',$current_time);
}
//Finally add end date to list, array contains all dates in order
$date_list[] = $end_date;

Basically, convert the dates to timestamps and add a day on each loop.

Upvotes: 1

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