SilverCloud, as the executive authority on the Two Kingdom's setting, you have the power and responsibility to establish key setting details, such as a functional calendar and the names of the capital cities of Dalen and Verden.
Regarding the calendar, I'd argue that it doesn't have to be realistic, as the fact that everyone speaks English most certainly is not realistic. You can feel free to use a calendar system that we are all familiar with if you don't want to create an original one.)
From Nim
Well, to be honest I don't believe it makes much of a difference which calendarsystem we're going to use so I think it will be most practical to use the one we all already know, unless someone have a brilliant idea of some other system.
As for all the other details of the game, I'm not a fan of creating the entire universe in too many details in advance, but want it to be a place where all members will have the oppotunity to add their ideas and by working together, creating it piece by piece. With that said, I still want to go through all of your ideas before they are being implemented in the game to make sure that the different ideas are going to work out together.
But, as I wrote a couple of days ago, I am quite busy but will be trying to make a post about all of it soon if I get the time, though I'll still be prioritising the storylines, which is the thing that keeps me going at the moment.
(Sorry I made this into a separate post, but I just figured it would be easier this way)