With all this theorizing about dates, I have to wonder... When have BoC releases coincided with special dates?
The only examples I can think of were the originally announced 6-6-06 date for the Trans Canada Highway release (which didn't end up actually being the release date) and the date the first TH transmission record was discovered- 4/20, Were Day + Record Store Day.
That's pretty much it.
The only thing that possibly points to the Jan. 22 date is the Turn That Smile Upside Down video, with still unidentified music, that appears to suggest an eclipse, Edinburgh being right in the path of totality for an eclipse on that date. That, the Pioneer Plaque banner, and the same date being the last transmission from the Pioneer, are the facts that actually set this date apart as a real possibility.
All these other dates- anniversaries of releases, astrological & astronomical events, etc. really have nothing going for them, because, for all the numerological references on their records, BoC have never seemed particularly concerned with release dates.