Schradinger said
Ah, right. I'm not sure exactly... I haven't done any estimates on travel time yet. I was going to write their arrivals in my next post.
I think you should receive message of the invasion around the 12th.
It will take you more than a week (I'm leaning toward 2 weeks) to ready up the legion and send them to Skyrim border. I have a new Skyrim player coming in soon, so you need to talk to them before your troops cross over.
Also, your horse-riding messengers will arrive in High Rock after 4-5 days, Hammerfell 5-6 days.