Detect overlapping periods php

Detect overlapping periods php

$final_selected_time = ["10:20-11:30","11:20-12:40","15-20","16:00"];

$results = [];
            sort($final_selected_time, SORT_NUMERIC);
            foreach ($final_selected_time as $k => $first) {
                $firstNums = explode("-", $first);
                foreach ($final_selected_time as $second) {
                    if ($first == $second) continue;
                    $secondNums = explode("-", $second);
                    if ($firstNums[0] <= $secondNums[0] && $secondNums[0] <= $firstNums[1]) {
                        // $results[$first] = $second;
                        $results[] = $secondNums[0];
                    }
                }
            }
            
  // output
  11:20 
  
  
  source link
  https://stackoverflow.com/questions/37788249/detect-overlapping-periods-php