Hey Andrew, I know it's late, but one other suggestion.
Would it be possible to add week numbers (along the left hand side) ? We use week numbers at work a lot ("Testing for the project is scheduled to start week 46") - and I've thought it might be a common thing in the Traveller universe since jumps take a week... ("Our schedule has us in Regina on weeks 5, 11, 17, and 24, then we spend the next half of the year on our rimward route.")
Just the plain week number, 1-52, would be cool. Then I could use it at work and impress my friends with the cool artwork.
Way late with this but I do hope Imperial holidays and notable dates are included on the calendar. Celebrating Strephon's birthday or marking the anniversary of the end of the 5th Frontier War would be a hoot.
I routinely celebrate the special dates found on the Three Stooges calendars I buy every year. Toasting Shemp's birthday is always an ice breaker.
I am in agreement with far-trader and Plankowner regarding the Julian (sequential) dates; it's a great idea. When does this baby go to press, and how may I get a copy?