That is a great point FTN - on the spyder site it states
"Unlike other crawlers, the data provided by the Spyder is always fresh information!
Never over a month old, users always receive the most relevant data and, at any time, may request a new crawl."
That would coincide with the fact that the countdown is such an odd # at 28 days. a typical February is the shortest month at 28 days and the quote from their ad site states the 'data is never more than a month old'. so i think youre right, it signifies if it just hit you its coming again within 28 days... that is actually very encouraging as it supports everyone who states it is a functioning tool right now and most likely bringing in good revs already.