WordPress底部添加运行时间

<span class="container">本站顽强的存活了</span>
            <SPAN id=span_dt_dt style="color: #2F889A;"></SPAN>
            <SCRIPT language=javascript>function show_date_time(){
                    window.setTimeout("show_date_time()", 1000);
                    BirthDay=new Date("6/10/2018 11:31:2");
                    today=new Date();
                    timeold=(today.getTime()-BirthDay.getTime());
                    sectimeold=timeold/1000
                    secondsold=Math.floor(sectimeold);
                    msPerDay=24*60*60*1000
                    e_daysold=timeold/msPerDay
                    daysold=Math.floor(e_daysold);
                    e_hrsold=(e_daysold-daysold)*24;
                    hrsold=Math.floor(e_hrsold);
                    e_minsold=(e_hrsold-hrsold)*60;
                    minsold=Math.floor((e_hrsold-hrsold)*60);
                    seconds=Math.floor((e_minsold-minsold)*60);
                    span_dt_dt.innerHTML='<font style=color:#C40000>'+daysold+'</font> 天 <font style=color:#C40000>'+hrsold+'</font> 时 <font style=color:#C40000>'+minsold+'</font> 分 <font style=color:#C40000>'+seconds+'</font> 秒';
                }
                show_date_time();