bobpeers -> blog

I’ve recently written an ASP.NET page using C# that required displaying the server time on the webpage using Javascript. To do this you need to output the Javascript code using C# and initialise the Javascript Date() object with the server time, after playing around I found this code does the job.

"server_time = new Date('" + DateTime.Now.ToString("MMMM d, yyyy HH:mm:ss") + "');"

The entire code looks like this assuming you have a label with id=’clock’ on the page. Just output the string js to the page to add the clock.

const string crlf = "\r\n";
string js = "<script type='text/javascript'>" + crlf +
"window.onload=startclock;" + crlf +
"var clock;" + crlf +
"var time_diff;" + crlf +
"function startclock(){" + crlf +
   "clock=document.getElementById('clock');" + crlf +
   "server_time = new Date('" + DateTime.Now.ToString("MMMM d, yyyy HH:mm:ss") + "');" + crlf +
   "time_diff=new Date()-server_time;" + crlf +
   "setInterval('runclock()',1000);" + crlf +
"}" + crlf +
"function runclock(){" + crlf +
   "var cDate=new Date();" + crlf +
   "cDate.setTime(cDate.getTime()-time_diff);" + crlf +
   "var curr_hours = cDate.getHours();" + crlf +
   "var curr_mins = cDate.getMinutes();" + crlf +
   "var curr_secs = cDate.getSeconds();" + crlf +
   "curr_hours=(curr_hours < 10)?'0' + curr_hours:curr_hours;" + crlf +
   "curr_mins=(curr_mins < 10)?'0' + curr_mins:curr_mins;" + crlf +
   "curr_secs=(curr_secs < 10)?'0' + curr_secs:curr_secs;" + crlf +
   "clock.innerHTML=curr_hours+':'+curr_mins+':'+curr_secs;" + crlf +
   "}" + crlf +
"</script>";

I should mention that if you’re using classic ASP and VBScript then the line becomes.

"server_time = new Date(" & DatePart("yyyy",Date) & "," & DatePart("m",Date)-1 & "," & DatePart("d",Date) & "," & DatePart("h",Now) & "," & DatePart("n",Now) & "," & DatePart("s",Now) & ");"