Se gostar basta copiar o código e colar e customizar na sua página.
<script language="javascript1.2">
var date = new Date();
var timegmt = date.toGMTString();
time_string = timegmt.split(' ');
week = time_string[0];
day = time_string[1];
mon = time_string[2];
year = time_string[3];
hms = time_string[4];
hms_string = hms.split(':');
var hour = hms_string[0] - 0;
var min = hms_string[1];
</script>
<script language="javascript1.2">
var loc_hour = date.getHours();
var loc_ampm = "";
if (loc_hour > 11) {
loc_ampm = ""
}
if (loc_hour > 24) {
loc_hour -= 12
}
document.write('<font size=1>HORA LOCAL: </font>');
document.write(loc_hour + ':' + min + loc_ampm);
document.write('<font size=1></font>');
</script>
var date = new Date();
var timegmt = date.toGMTString();
time_string = timegmt.split(' ');
week = time_string[0];
day = time_string[1];
mon = time_string[2];
year = time_string[3];
hms = time_string[4];
hms_string = hms.split(':');
var hour = hms_string[0] - 0;
var min = hms_string[1];
</script>
<script language="javascript1.2">
var loc_hour = date.getHours();
var loc_ampm = "";
if (loc_hour > 11) {
loc_ampm = ""
}
if (loc_hour > 24) {
loc_hour -= 12
}
document.write('<font size=1>HORA LOCAL: </font>');
document.write(loc_hour + ':' + min + loc_ampm);
document.write('<font size=1></font>');
</script>