End date broken and events don't show on calendar after July 1 update

I can confirm this bug on a 3-days fresh Drupal installation. Non-core modules installed: CCK, Views, Advanced Help and Event 6.x-2.x-dev.

I had a similar problem. When the minutes in either the start date or the end date was 00, it would be read as a single integer '0' and never got converted to a 2-char string. A symptom is that preview would display the time as "12:0" or "1:0" instead of "12:00" or "1:00". This is not fixed by the time it gets to the INSERT line. MySQL does not know how to read a time of "12:0:00" and the database ends up with a value that is either null or all zeroed out.

I have modified the event_explode_date and event_implode_date to be sure that all affected strings are padded out to two characters. I do not know how to submit a patch, so I will post my code here. event_explode_date is at line 2789 and implode is the next function after it.

function event_explode_date($date) {
  $return = array();
  if (function_exists('date_parse')) {
    $return = date_parse($date);
  }
  else {
    // Forcibly parse the date
    list($date, $time) = explode(' ', $date);

    // make it work for "time only" and "date only" values as well
    if (!isset($time)) {
      if (strpos($date, '-') ) {
        $time = '00:00:00';
      }
      else {
        $time = $date;
        $date = '--';
      }
    }

    // Add the data to the $return array in the same format as parse_date() does
    list($year, $month, $day) = explode('-', $date);
    $return['year'] = $year;
    $return['month'] = $month;
    $return['day'] = $day;
    list($hour, $minute, $second) = explode(':', $time);
    $return['hour']=$hour;
    $return['minute']=$minute;
    $return['second']=$second;
  }
  // Pad values that need padding and return the date as an associative array
  $return['month'] = str_pad($return['month'], 2, '0', STR_PAD_LEFT);
  $return['day'] = str_pad($return['day'], 2, '0', STR_PAD_LEFT);
  $return['hour'] = str_pad($return['hour'], 2, '0', STR_PAD_LEFT);
  $return['minute'] = str_pad($return['minute'], 2, '0', STR_PAD_LEFT);
  $return['second'] = str_pad($return['second'], 2, '0', STR_PAD_LEFT);
  return $return;
}

function event_implode_date($date) {
  if (!isset($date['second'])) {
    $date['second'] = '00';
  }
  return $date['year'] .'-'
        . str_pad($date['month'], 2, '0', STR_PAD_LEFT) .'-'
        . str_pad($date['day'], 2, '0', STR_PAD_LEFT) .' '
        . str_pad($date['hour'], 2, '0', STR_PAD_LEFT) .':'
        . str_pad($date['minute'], 2, '0', STR_PAD_LEFT) .':'
        . str_pad($date['second'], 2, '0', STR_PAD_LEFT) ;
}

These revised functions will repair the minutes before it is shown in preview and before it is saved to the database. The place to really fix the problem is where the form submission is read in and the original values created, but I can not find where that is.

In http://drupal.org/node/278768 which may be related to this, wdrout has a patch which attacks a similar problem through the expand_event() function. Someone who knows how the module works should have a look at his patch before considering my submissions.
http://drupal.org/files/issues/event.module_66.patch

This seemed to go away when I set my site's default timezone. (Oops.)

Edit: I also had to set the default time formats to am/pm readouts. It seems totally fixed now.

http://drupal.org/node/267018

This has most likely been fixed in the latest release. If you are still having problems, tell us your timezone setting and the details of any test cases where the problem does or does not happen.