Analyzes an array of date/time stamps to try and make a "best" guess on when the next date/time stamp will be.

sequence-analyzing.php

function get_average($time_array)
 {
      $total = "";
      $last = "";
      $count = count($time_array);
      for($t=0;$t<$count;$t++)
      {
           $time = $time_array[$t];
           if($t == 0)
           {
                $last = $time;
           } else {
                $diff = get_diff($last, $time);
                $last = $time;
                $total += $diff;
           }
      }
      $average = ($total/($count-1));
      return round($average);
 }

 function get_diff($time1, $time2)
 {
      $t1 = strtotime($time1);
      $t2 = strtotime($time2);
      $diff = ($t2 - $t1)/60;
      return $diff;
 }

 function guess_next($date_array)
 {
      $diff_avg = get_average($date_array);
      $last_date = new DateTime(end($date_array));
      $last_date->add(new DateInterval('PT'.$diff_avg.'M'));
      $next = $last_date->format('m/d/Y H:i');
      return $next;
 }

 $date_stamps = array(
      "5/10/2013 9:30",
      "5/11/2013 9:50",
      "5/12/2013 10:20",
      "5/13/2013 10:59",
      "5/14/2013 11:22",
      "5/15/2013 11:51",
      "5/16/2013 12:28",
      "5/17/2013 12:57",
      "5/18/2013 13:13");

 print(guess_next($date_stamps));