PHP中的库函数将实时计时器放入其中

is it possible to place a live timer in PHP page is their any library Function for it and timer get refresed without whole page getting refresed

You can use ajax if you want particular div to get refresh. But from my experience you should use javascript instead of PHP.

You can use jquery timer library and implement the same as under

<script type="text/javascript" src="jquery.min.js"></script>
<script type="text/javascript" src="jquery.timer.js"></script>

<script type="text/javascript"> 

        var seconds = <?php echo 600; ?>;


        var timer = $.timer(
        function() {
            seconds--;


            var hr=Math.floor(seconds/(60*60));
            var min=Math.floor((seconds / 60) % 60);
            var sec=seconds % 60; 

            <?php

            $_session['hr']=hr;
            $_session['min']=min;
            $_session['sec']=sec;

            ?>
            $('.count').html(hr+ " : " + min + ":" + sec);
        },
        1000,   
        true
    );  




    </script> 

    <div class="count">

    </div>

The js file you can find it here