javascript - Change innerHTML based on date comparison -

i have following code showing:

<h1  id="header1" class="loginhead">welcome <%=formfields.getdisplayvalue("programname")%> registration site, .</h1>  

i need replace with:

<h1  id="header2" class="loginhead" >the <%=formfields.getdisplayvalue("programname")%> registration site, closed.</h1>  

i need replace happen when date , time 7/15/15 11:59pm pt

any way using jquery, jsp or javascript?

update**

    <h1  id="header" class="loginhead" ><span id='welcome'></span><span id='welcome2'></span> <%=formfields.getdisplayvalue("programname")%> registration site <span id='closed'></span> </h1>  <script>  var = new date().gettime(); //return number of milliseconds since 1970/01/01:  var epochtimejul15_1159pm = 1437019199000; // number of milliseconds since 1970/01/01 @ jul 15_11:59:59pm. see http://www.epochconverter.com/.  var timetillchange = epochtimejul15_1159pm - now;  function changeheader(){     document.getelementbyid('closed').innerhtml = ' closed.'; //change html/text inside of span id closed'. }  function changeheader1() {     if(epochtimejul15_1159pm <= now)      {         document.getelementbyid('welcome').innerhtml = 'the ';     } }  function changeheader2() {     if(now < epochtimejul15_1159pm)      {         document.getelementbyid('welcome2').innerhtml = 'welcome ';      } } settimeout(changeheader, timetillchange); //will wait call changeheader function until timetillchange milliseconds have occured. settimeout(changeheader1, timetillchange);  settimeout(changeheader2, timetillchange); </script> 

first make easier use javascript edit html. creating empty span insert closed message into:

<h1  id="header" class="loginhead" >welcome <%=formfields.getdisplayvalue("programname")%> registration site <span id='closed'></span> </h1>  

now in javascript section:

var = new date().gettime(); //return number of milliseconds since 1970/01/01:  var epochtimejul15_1159pm = 1437019199000; // number of milliseconds since 1970/01/01 @ jul 15_11:59:59pm. see http://www.epochconverter.com/.  var timetillchange = epochtimejul15_1159pm - now;  function changeheader(){     document.getelementbyid('closed').innerhtml = ' closed.'; //change html/text inside of span id closed'. }  settimeout(changeheader, timetillchange); //will wait call changeheader function until timetillchange milliseconds have occured. 

this make header edited live clock hits 11:59:59.