Possible problems? Our national debt clock, which works the same way, is used by hundreds including one Senator. This is the only reported problem:
If you page has another JaveScript clock or google ads (which run on JS).
Users of older versions of Firefox (before 1.5).
May seem some page text jump and ficker ever four to eight clock ticks.
If you are worried about this, then make an iFrame and put the clock in the html inside the iFrame. Below is an iFrame tag that will work, if you
1) Adjust the width and height to suit your content.
2) Put the name of your html page for the clock as the "src="
3) Put the HTML and JS from the window on the main Fossil-Clock page
into your html page for the clock.
zFacts does not bother to use iFrames for clocks on it's site.
Here is an iFrame using the Fossil Clock:
It uses the iFrame tag and HTML file shown below.
The background colors are just to help you size the iFrame.
Here's the exact iFrame tag used:
And, here's the exact HTML used (from zfacts.com/giz/G11/G11basic.html):
