public function DateObject::difference in Date 7

Same name and namespace in other branches

1. 7.3 date_api/date_api.module \DateObject::difference()
2. 7.2 date_api/date_api.module \DateObject::difference()

Compute difference between two days using a given measure.

Parameters

mixed $date1: the starting date

mixed $date2: the ending date

string $measure: 'years', 'months', 'weeks', 'days', 'hours', 'minutes', 'seconds'

string $type: the type of dates provided: DATE_OBJECT, DATE_DATETIME, DATE_ISO, DATE_UNIX, DATE_ARRAY

File

date_api/date_api.module, line 638

This module will make the date API available to other modules. Designed to provide a light but flexible assortment of functions and constants, with more functionality in additional files that are not loaded unless other modules specifically include them.

Class

DateObject

Extend PHP DateTime class with granularity handling, merge functionality and slightly more flexible initialization parameters.

Code

public function difference($date2_in, $measure = 'seconds') {

  // Create cloned objects or original dates will be impacted by
  // the date_modify() operations done in this code.
  $date1 = clone $this;
  $date2 = clone $date2_in;
  if (is_object($date1) && is_object($date2)) {
    $diff = date_format($date2, 'U') - date_format($date1, 'U');
    if ($diff == 0) {
      return 0;
    }
    elseif ($diff < 0) {

      // Make sure $date1 is the smaller date.
      $temp = $date2;
      $date2 = $date1;
      $date1 = $temp;
      $diff = date_format($date2, 'U') - date_format($date1, 'U');
    }
    $year_diff = intval(date_format($date2, 'Y') - date_format($date1, 'Y'));
    switch ($measure) {

      // The easy cases first.
      case 'seconds':
        return $diff;
      case 'minutes':
        return $diff / 60;
      case 'hours':
        return $diff / 3600;
      case 'years':
        return $year_diff;
      case 'months':
        $format = 'n';
        $item1 = date_format($date1, $format);
        $item2 = date_format($date2, $format);
        if ($year_diff == 0) {
          return intval($item2 - $item1);
        }
        else {
          $item_diff = 12 - $item1;
          $item_diff += intval(($year_diff - 1) * 12);
          return $item_diff + $item2;
        }
        break;
      case 'days':
        $format = 'z';
        $item1 = date_format($date1, $format);
        $item2 = date_format($date2, $format);
        if ($year_diff == 0) {
          return intval($item2 - $item1);
        }
        else {
          $item_diff = date_days_in_year($date1) - $item1;
          for ($i = 1; $i < $year_diff; $i++) {
            date_modify($date1, '+1 year');
            $item_diff += date_days_in_year($date1);
          }
          return $item_diff + $item2;
        }
        break;
      case 'weeks':
        $week_diff = date_format($date2, 'W') - date_format($date1, 'W');
        $year_diff = date_format($date2, 'o') - date_format($date1, 'o');
        for ($i = 1; $i <= $year_diff; $i++) {
          date_modify($date1, '+1 year');
          $week_diff += date_iso_weeks_in_year($date1);
        }
        return $week_diff;
    }
  }
  return NULL;
}