Reader Jason points us toward this lovely calendar for sale. He saw it originally at Menards and was able to find a copy of the cover online. Most things about it sound pretty standard from the description:
Minnesota Twins 2013 Calendar features a month at a time view of the Minnesota Twins. Each month features a full color picture of Twins players. There is a bonus section of a September-December, 2012 Calendar in the beginning. It also shows exciting Twins Trivia Questions and important MLB dates.
Perhaps the only quibble: Francisco Liriano is on the cover. Surely the manufacturer had to pre-produce these. But surely someone along the way could have noted that of all the players on the 2012 Twins who might be calendar-cover worthy, Liriano was perhaps the least likely to be around in 2013. (Also: Denard Span and Justin Morneau, though still with the team at this time, could be dealt in the offseason as well. If Mauer somehow goes, too, this thing will be a collector's item before the season even starts).
Know who could straighten these calendar people out? Don Cooper.