php - Omitting redundant months and years in date range list -

i have got strange issue dates of events , have tried hard fixed unable it.

i attaching screenshot of how want display dates on page :

in picture first event deine energie in aktion! combination of 5 events each event having start date , end date.

the first part of event 1 day event starts on 4th april , ends on 4th april. second part on 7th april, 3rd part on 9th april , 4th part on 20th april

the last part starts on 5th may , ends on 10th may.

the dates stored in database in format : showing dates last part of event. event start date : 2013-05-05 00:00:00 event end date : 2013-05-10 00:00:00

so want display dates in format shown in picture.

there multiple cases: first if dates coming within single month display month name @ end once. second if months changed month name shown after date when month changed.

i getting events dates in while loop, how compare current event date coming event date in loop.

this code have used far dates database..

    $nid = $row->nid;   $get_product_id = "select product_id {uc_product_kits} nid='$nid'"; $res = db_query($get_product_id); while ($get_product_id_array_value = db_fetch_array($res)) {     $prductid = $get_product_id_array_value['product_id'];     $start_date = db_query("select event_start,event_end {event} nid=%d",$prductid);     $start_date_value = db_fetch_object($start_date);     $end_value = $start_date_value->event_start;      $event_end_date = $start_date_value->event_end;     $totalstart =  date("d m y", strtotime($end_value));     $totalend = date("d m y", strtotime($event_end_date));     $onlymonthstart =  date("m", strtotime($end_value));     $onlymonthend = date("m", strtotime($event_end_date));     //$groupmonth = db_query("select event_start,event_end, month  {event} nid=%d group ",$prductid);     if($totalstart == $totalend ){         $startday = date("d", strtotime($end_value));         $startmonth = date("m", strtotime($end_value));         if(in_array($startmonth,$newmonth)) {             echo $onlstartdate;         }          else {               $onlstartdate =  date("d", strtotime($end_value));              echo $onlstartdate;              $tempstorage[] = $startmonth         }         //$newmonth[] = $startmonth;     } } 

easiest first collect data query e.g. array.

only iterate on array. having data allow compare 2 consecutive date ranges decide level of details need print each.

commented example:

// collect data sql query structure this:  $events = array(     array("event_start" => "2013-4-4", "event_end" => "2013-4-4"),     array("event_start" => "2013-4-7", "event_end" => "2013-4-7"),     array("event_start" => "2013-4-9", "event_end" => "2013-4-9"),     array("event_start" => "2013-4-20", "event_end" => "2013-4-20"),     array("event_start" => "2013-5-5", "event_end" => "2013-5-10"),     array("event_start" => "2014-1-1", "event_end" => "2014-1-2"), );  // actual code range list generation:  ($i = 0; $i < count($events); $i++) {     // parse start , end of range     $this_event = $events[$i];     $this_start_date = strtotime($this_event["event_start"]);     $this_end_date = strtotime($this_event["event_end"]);      // extract months , years     $this_start_month = date("m", $this_start_date);     $this_end_month = date("m", $this_end_date);     $this_start_year = date("y", $this_start_date);     $this_end_year = date("y", $this_end_date);      $last = ($i == count($events) - 1);     // parse start , end of next range, if     if (!$last)     {         $next_event = $events[$i + 1];         $next_start_date = strtotime($next_event["event_start"]);         $next_end_date = strtotime($next_event["event_end"]);          $next_start_month = date("m", $next_start_date);         $next_end_month = date("m", $next_end_date);         $next_start_year = date("y", $next_start_date);         $next_end_year = date("y", $next_end_date);     }      // ranges different starting , ending months go     // on own line     if (($this_start_month != $this_end_month) ||         ($this_start_year != $this_end_year))     {         echo date("j m", $this_start_date);         // print starting year if differs ending year         if ($this_start_year != $this_end_year)         {             echo " ".date("y", $this_start_date);         }         echo "-".date("j m y", $this_end_year)." <br/>\n";     }     else     {         // range starting , ending in same month          echo date("j", $this_start_date);         // different starting , ending day         if ($this_start_date != $this_end_date)         {             echo "-".date("j", $this_end_date);         }          $newline = false;         // print month last range;         // , range starts(=ends) in different month         // next range ends         if ($last ||             ($this_start_month != $next_end_month))         {             echo " ".date("m", $this_start_date);             $newline = true;         }          // print year last range;         // , range starts(=ends) in different year         // next range ends         if ($last ||             ($this_start_year != $next_end_year) ||             ($next_start_month != $next_end_month))         {             echo " ".date("y", $this_start_date);             $newline = true;         }          if ($newline)         {             echo " <br/>\n";         }         else         {             // month (and year) printed future range             // on same line             echo ", ";         }     } } 

this outputs:

4, 7, 9, 20 apr <br/> 5-10 may 2013 <br/> 1-2 jan 2014 <br/>