I'm no expert on these, but of the one's listed at FE:
TMBTM's 30's Serial edits: Oct 2008
Lewis886's Rise of the Empire: October 2007
Blankfist's The Fall of the Republic: June 2007
I'm no Rebecca Black, but my understanding of the basic function of calendars leads me to believe that these came first.
But I have been known to be wrong...
From time to time..