diff --git a/packages/zend-timesync/library/Zend/TimeSync/Ntp.php b/packages/zend-timesync/library/Zend/TimeSync/Ntp.php
index 139d1c66b..dfb87bbad 100644
--- a/packages/zend-timesync/library/Zend/TimeSync/Ntp.php
+++ b/packages/zend-timesync/library/Zend/TimeSync/Ntp.php
@@ -56,28 +56,49 @@ public function __construct($timeserver, $port = 123)
     }
 
     /**
-     * Prepare local timestamp for transmission in our request packet
+     * Convert microtime (result of microtime() as string "msec sec") to NTP timestamp
      *
      * NTP timestamps are represented as a 64-bit fixed-point number, in
      * seconds relative to 0000 UT on 1 January 1900.  The integer part is
      * in the first 32 bits and the fraction part in the last 32 bits
      *
+     * @param string $microtime
      * @return string
      */
-    protected function _prepare()
+    public static function microtimeToNtp($microtime)
     {
-        list($frac, $sec) = explode(' ', microtime());
+        list($frac, $sec) = explode(' ', $microtime);
+        $frac = (int) round((float) $frac * 0x100000000); // represent fraction in 0:(2^32)-1 range (32bit)
         $fracba = ($frac & 0xff000000) >> 24;
         $fracbb = ($frac & 0x00ff0000) >> 16;
         $fracbc = ($frac & 0x0000ff00) >> 8;
         $fracbd = ($frac & 0x000000ff);
 
-        $sec = $sec + 2208988800;
+        $sec = $sec + 2208988800; // add 70 years in seconds, as ntp counts from 1900
         $secba = ($sec & 0xff000000) >> 24;
         $secbb = ($sec & 0x00ff0000) >> 16;
         $secbc = ($sec & 0x0000ff00) >> 8;
         $secbd = ($sec & 0x000000ff);
 
+        $ntp  = chr($secba)  . chr($secbb)  . chr($secbc)  . chr($secbd);
+        $ntp .= chr($fracba) . chr($fracbb) . chr($fracbc) . chr($fracbd);
+
+        return $ntp;
+    }
+
+    /**
+     * Prepare local timestamp for transmission in our request packet
+     *
+     * NTP timestamps are represented as a 64-bit fixed-point number, in
+     * seconds relative to 0000 UT on 1 January 1900.  The integer part is
+     * in the first 32 bits and the fraction part in the last 32 bits
+     *
+     * @return string
+     */
+    protected function _prepare()
+    {
+        $ntptime = self::microtimeToNtp(microtime());
+
         // Flags
         $nul       = chr(0x00);
         $nulbyte   = $nul . $nul . $nul . $nul;
@@ -110,8 +131,7 @@ protected function _prepare()
          * The local time, in timestamp format, at the peer when its latest NTP message
          * was sent. Contanis an integer and a fractional part
          */
-        $ntppacket .= chr($secba)  . chr($secbb)  . chr($secbc)  . chr($secbd);
-        $ntppacket .= chr($fracba) . chr($fracbb) . chr($fracbc) . chr($fracbd);
+        $ntppacket .= $ntptime;
 
         /*
          * The local time, in timestamp format, at the peer. Contains an integer
@@ -132,8 +152,7 @@ protected function _prepare()
          * NTP message departed the sender. Contanis an integer
          * and a fractional part.
          */
-        $ntppacket .= chr($secba)  . chr($secbb)  . chr($secbc)  . chr($secbd);
-        $ntppacket .= chr($fracba) . chr($fracbb) . chr($fracbc) . chr($fracbd);
+        $ntppacket .= $ntptime;
 
         return $ntppacket;
     }
diff --git a/tests/Zend/TimeSyncTest.php b/tests/Zend/TimeSyncTest.php
index 4164fef56..429412395 100644
--- a/tests/Zend/TimeSyncTest.php
+++ b/tests/Zend/TimeSyncTest.php
@@ -344,4 +344,10 @@ public function testGetInfo()
             // nothing
         }
     }
+
+    public function testMicrotimeToNtp()
+    {
+        $ntp = Zend_TimeSync_Ntp::microtimeToNtp('0.123456 1234567890');
+        $this->assertSame(pack('NN', 0xcd408152, 0x1f9acffa), $ntp);
+    }
 }