Tiempo transcurrido entre dos fechas con php

Buenas!

PHP dispone de funciones para calcular el tiempo transcurrido, pero si necesitas llegar a un nivel de detalle tan tan bajo como ese te dejo una función ya programada para ello

public function timeAgoDate($datefrom, $dateto = -1)
 {
    // Defaults and assume if 0 is passed in that
    // its an error rather than the epoch
 
    if ($datefrom <= 0) { 
      return "A long time ago"; 
    }
 
    if($dateto==-1) { 
      $dateto = time(); 
    }
 
    // Calculate the difference in seconds betweeen
    // the two timestamps
 
    $difference = $dateto - $datefrom;
 
    // If difference is less than 60 seconds,
    // seconds is a good interval of choice
 
    if($difference < 60) {
      $interval = "s";
    }
 
    // If difference is between 60 seconds and
    // 60 minutes, minutes is a good interval
    elseif($difference >= 60 && $difference < 60*60) {
      $interval = "n";
    }
 
    // If difference is between 1 hour and 24 hours
    // hours is a good interval
    elseif($difference >= 60*60 && $difference < 60*60*24) {
      $interval = "h";
    }
 
    // If difference is between 1 day and 7 days
    // days is a good interval
    elseif($difference >= 60*60*24 && $difference < 60*60*24*7) {
      $interval = "d";
    }
 
    // If difference is between 1 week and 30 days
    // weeks is a good interval
    elseif($difference >= 60*60*24*7 && $difference < 60*60*24*30) {
      $interval = "ww";
    }
 
    // If difference is between 30 days and 365 days
    // months is a good interval, again, the same thing
    // applies, if the 29th February happens to exist
    // between your 2 dates, the function will return
    // the 'incorrect' value for a day
    elseif($difference >= 60*60*24*30 && $difference < 60*60*24*365) {
      $interval = "m";
    }
 
    // If difference is greater than or equal to 365
    // days, return year. This will be incorrect if
    // for example, you call the function on the 28th April
    // 2008 passing in 29th April 2007. It will return
    // 1 year ago when in actual fact (yawn!) not quite
    // a year has gone by
    elseif($difference >= 60*60*24*365) {
      $interval = "y";
    }
 
    // Based on the interval, determine the
    // number of units between the two dates
    // From this point on, you would be hard
    // pushed telling the difference between
    // this function and DateDiff. If the $datediff
    // returned is 1, be sure to return the singular
    // of the unit, e.g. 'day' rather 'days'
 
    switch($interval) {
      case "m":
        $months_difference = floor($difference / 60 / 60 / 24 / 29);
        while (mktime(date("H", $datefrom), date("i", $datefrom),
          date("s", $datefrom), date("n", $datefrom) + ($months_difference),
          date("j", $dateto), date("Y", $datefrom)) < $dateto) {
 
          $months_difference++;
        }
        $datediff = $months_difference;
 
        // We need this in here because it is possible
        // to have an 'm' interval and a months
        // difference of 12 because we are using 29 days
        // in a month
 
        if($datediff == 12) {
          $datediff--;
        }
 
        $res = ($datediff==1) ? "$datediff month ago" : "$datediff months ago";
      break;
 
      case "y":
        $datediff = floor($difference / 60 / 60 / 24 / 365);
        $res = ($datediff==1) ? "$datediff year ago" : "$datediff years ago";
      break;
 
      case "d":
        $datediff = floor($difference / 60 / 60 / 24);
        $res = ($datediff==1) ? "$datediff day ago" : "$datediff days ago";
      break;
 
      case "ww":
        $datediff = floor($difference / 60 / 60 / 24 / 7);
        $res = ($datediff==1) ? "$datediff week ago" : "$datediff weeks ago";
      break;
 
      case "h":
        $datediff = floor($difference / 60 / 60);
        $res = ($datediff==1) ? "$datediff hour ago" : "$datediff hours ago";
      break;
 
      case "n":
        $datediff = floor($difference / 60);
        $res = ($datediff==1) ? "$datediff minute ago" : "$datediff minutes ago";
      break;
 
      case "s":
        $datediff = $difference;
        $res = ($datediff==1) ? "$datediff second ago" : "$datediff seconds ago";
      break;
    }
    return $res;
}

Joe tio, que no te di las gracias y mira que he vuelto a este hilo a pillar la función bastantes veces.. funciona a la perfección! :)