Simple SSI code works on main domain pages but not subdomain

[perplexed]

For years i have had a simple piece of 'Server Side Includes' code that displays the date on pretty much each page of my site. This has always worked and still is working perfectly on my main domain. However, i've just noticed that three pages which are exact copies of three on my main site, but are on pages in a subdomain don't show the date. Does this mean i need to set something within the subdomain settings?

I've just been navigating through the laboriously slow and (to me) confusing plesk interface and am going round in circles trying to find what needs to done

The code snippet is Server Side Includes

<!-- #echo var="DATE_GMT" -->

Everything but the date is ok all three pages are word for word the same as on the main domain. It will show,

'Today's Date Is ~~~If this is not today's date, refresh page for updated version.', which omits the date.

The pages on the main domain show,

'Today's Date Is Thursday July 08 2010~~~If this is not today's date, refresh page for updated version'.

I'm using the Windows Shared Hosting.

Anybody any ideas as to the problem?

[PatrickP]

If the sub-domain is created as a physical hosting then it creates a folder outside httpdocs directory of your main site.So I would request you to use a separate .htaccess file under this sub-domain and append the above SSI code and check if this works for you.

[sysadmin]

Hi Paul,

Could you please make sure that you've having the sub domain's set to use SSI?

ie: Login to Plesk > Click on your main domain > Sub Domains > sample-sub-domain.com > Setup > SSI