Guild Wars 2

How long will the instances at each city last? As in can they be completed between 10am start till the 10am start of a different city? Can you get the achievement at any time during this period? If you miss a day can you get the achievement at the end when you have the opportunity to replay these instances?

Not sure how long they last, but I know that when Tixx reaches LA, you can replay any city that you missed. So if you miss out on one, you can just wait till then.

As far as I understand, he will stay until 10 am the next day, when he moves to the next city.