A day early and a gross of years late

With the same breathless excitement in which Navin Johnson announced the arrival of updated phone books, I excitedly declare:

The new Tube maps are here!
The new Tube maps are here!

These free pocket maps of the Underground are available at (nearly) every Tube station, and Underground enthusiasts (like me!) collect 'em all, even the current ones. So you can imagine my delight in Holland Park Station this morning when I saw for the first time that the previous map, dated September 2006, had been replaced by a new edition dated January 2007. One more thing to paste in my London scrapbook! I'm ever-so-keen on collecting and examining these maps in close detail, so only another Tubespotter will be interested in my observation that the January 2007 map deletes the detail of Stratford to North Woolwich National Rail line which is now under reconstruction to become part of Docklands Light Rail. Silvertown, we hardly knew ye!

What interests me more is the cover art of the map pamphlet. Transport for London generally designs their tube map brochures with stylized or slightly-abstract art in the brightly-colored shades of the Underground lines, and the January 2007 map is no different: while it appears at first glance to have invented the word "heighteen," a moment's examination tells us it actually says "Friday, January the Ninth, Eighteen-Sixty-Three."

Um, except...

...just what is that date supposed to be commemorating? Any Underground enthusiast will tell you that the Underground opened on January the Tenth, 1863 (with the first train service between Baker Street and Farringdon, along what was eventually the Metropolitan Line and now is known as the Hammersmith and City Line). So what is the map referring to with 9 January? The last day of the "old world" before London was transformed forever and thrust into the new age? An early, non-public test run of the Underground service? The night The Doctor and Rose arrived to stop the Dalek infestation of the tunnels so the trains could start on time the next morning?

Or did they just make a silly mistake?

EDIT on 1/9/07: Annie Mole from the unparalleled Going Underground's Blog also notes the new map here and references one of her earlier entries here that explains a ceremonial tour of the first stretch of the Underground took place on 9 January 1863.