http test question

Hi all.  Is it possible to control the times an HTTP URL test is performed?

I know I can add http://www.sample.com and use regexs to look for an occurrence of the word Fail, but we would only like it to check once or twice per day, say at 7:45 and then once more at 8:25.  I know its easy to control the timing of when the alert is sent.  But can I limit when the test is run?  Short of creating an ext-script, not sure how I do that in xymon.

Thanks,
Taylor