You mean an in-game resource for the current year and names of months? Not sure about mainland Unmei, but the Isle of Khar-Durai has been using common month names (January, February, etc.) . And I've always assumed "common reckoning" for year on Khar-Durai as well (623 currently).
I do believe Mainland Unmei/Cinderfel YEAR is 2384 currently. Not sure if they have their own month names, actually. Maybe Jeremy or Brian can fill in some details for ya too!