diff --git a/src/Symfony/Component/HttpKernel/Profiler/BaseMemcacheProfilerStorage.php b/src/Symfony/Component/HttpKernel/Profiler/BaseMemcacheProfilerStorage.php
index e71f436ba1..e3454f60f9 100644
--- a/src/Symfony/Component/HttpKernel/Profiler/BaseMemcacheProfilerStorage.php
+++ b/src/Symfony/Component/HttpKernel/Profiler/BaseMemcacheProfilerStorage.php
@@ -64,7 +64,7 @@ abstract class BaseMemcacheProfilerStorage implements ProfilerStorageInterface
 
             list($itemToken, $itemIp, $itemMethod, $itemUrl, $itemTime, $itemParent) = explode("\t", $item, 6);
 
-            $itemTime = (int)$itemTime;
+            $itemTime = (int) $itemTime;
 
             if ($ip && false === strpos($itemIp, $ip) || $url && false === strpos($itemUrl, $url) || $method && false === strpos($itemMethod, $method)) {
                 continue;
diff --git a/src/Symfony/Component/HttpKernel/Profiler/MemcacheProfilerStorage.php b/src/Symfony/Component/HttpKernel/Profiler/MemcacheProfilerStorage.php
index ebf3b5c2ac..91ce381374 100644
--- a/src/Symfony/Component/HttpKernel/Profiler/MemcacheProfilerStorage.php
+++ b/src/Symfony/Component/HttpKernel/Profiler/MemcacheProfilerStorage.php
@@ -20,7 +20,6 @@ use Memcache;
  */
 class MemcacheProfilerStorage extends BaseMemcacheProfilerStorage
 {
-
     /**
      * @var Memcache
      */
@@ -106,5 +105,4 @@ class MemcacheProfilerStorage extends BaseMemcacheProfilerStorage
 
         return $memcache->set($key, $content . $value, false, $expiration);
     }
-
 }
diff --git a/src/Symfony/Component/HttpKernel/Profiler/MemcachedProfilerStorage.php b/src/Symfony/Component/HttpKernel/Profiler/MemcachedProfilerStorage.php
index 34ca1cbcad..554a0ac194 100644
--- a/src/Symfony/Component/HttpKernel/Profiler/MemcachedProfilerStorage.php
+++ b/src/Symfony/Component/HttpKernel/Profiler/MemcachedProfilerStorage.php
@@ -20,7 +20,6 @@ use Memcached;
  */
 class MemcachedProfilerStorage extends BaseMemcacheProfilerStorage
 {
-
     /**
      * @var Memcached
      */
@@ -101,5 +100,4 @@ class MemcachedProfilerStorage extends BaseMemcacheProfilerStorage
 
         return $result;
     }
-
 }
diff --git a/src/Symfony/Component/HttpKernel/Profiler/Profiler.php b/src/Symfony/Component/HttpKernel/Profiler/Profiler.php
index f83358fbfe..ea93a24aea 100644
--- a/src/Symfony/Component/HttpKernel/Profiler/Profiler.php
+++ b/src/Symfony/Component/HttpKernel/Profiler/Profiler.php
@@ -163,29 +163,27 @@ class Profiler
      * @param string $url    The URL
      * @param string $limit  The maximum number of tokens to return
      * @param string $method The request method
-     * @param int    $start  The start period to search from
-     * @param int    $end    The end period to search to
+     * @param string $start  The start date to search from
+     * @param string $end    The end date to search to
      *
      * @return array An array of tokens
+     *
+     * @see http://fr2.php.net/manual/en/datetime.formats.php for the supported date/time formats
      */
     public function find($ip, $url, $limit, $method, $start, $end)
     {
-        if ($start != '' && null !== $start) {
-            if (is_integer($start)) {
-                $start = '@' . $start;
-            }
-
+        if ('' != $start && null !== $start) {
             $start = new \DateTime($start);
             $start = $start->getTimestamp();
+        } else {
+            $start = null;
         }
 
-        if ($end != '' && null !== $end) {
-            if (is_integer($end)) {
-                $end = '@' . $end;
-            }
-
+        if ('' != $end && null !== $end) {
             $end = new \DateTime($end);
             $end = $end->getTimestamp();
+        } else {
+            $end = null;
         }
 
         return $this->storage->find($ip, $url, $limit, $method, $start, $end);
diff --git a/src/Symfony/Component/HttpKernel/Profiler/ProfilerStorageInterface.php b/src/Symfony/Component/HttpKernel/Profiler/ProfilerStorageInterface.php
index 9352f9e1d2..3bb0d68ffd 100644
--- a/src/Symfony/Component/HttpKernel/Profiler/ProfilerStorageInterface.php
+++ b/src/Symfony/Component/HttpKernel/Profiler/ProfilerStorageInterface.php
@@ -21,12 +21,12 @@ interface ProfilerStorageInterface
     /**
      * Finds profiler tokens for the given criteria.
      *
-     * @param string $ip     The IP
-     * @param string $url    The URL
-     * @param string $limit  The maximum number of tokens to return
-     * @param string $method The request method
-     * @param int    $start  The start period to search from
-     * @param int    $end    The end period to search to
+     * @param string   $ip     The IP
+     * @param string   $url    The URL
+     * @param string   $limit  The maximum number of tokens to return
+     * @param string   $method The request method
+     * @param int|null $start  The start date to search from
+     * @param int|null $end    The end date to search to
      *
      * @return array An array of tokens
      */
diff --git a/src/Symfony/Component/HttpKernel/Profiler/RedisProfilerStorage.php b/src/Symfony/Component/HttpKernel/Profiler/RedisProfilerStorage.php
index 66da718212..1d2df5ccd1 100644
--- a/src/Symfony/Component/HttpKernel/Profiler/RedisProfilerStorage.php
+++ b/src/Symfony/Component/HttpKernel/Profiler/RedisProfilerStorage.php
@@ -74,7 +74,7 @@ class RedisProfilerStorage implements ProfilerStorageInterface
 
             list($itemToken, $itemIp, $itemMethod, $itemUrl, $itemTime, $itemParent) = explode("\t", $item, 6);
 
-            $itemTime = (int)$itemTime;
+            $itemTime = (int) $itemTime;
 
             if ($ip && false === strpos($itemIp, $ip) || $url && false === strpos($itemUrl, $url) || $method && false === strpos($itemMethod, $method)) {
                 continue;