I tried to book a flight today with Easyjet for the end of May but when I click 'Show flights' after entering the dates I wish to travel a box appears saying 'The route you have selected is for sale until 27 March 2010' & it won't let me go any further. Is this just a badly worded way of saying I can't book until 27 March 2010?
Easyjet's got a sale on at the moment finishing tonight for flights between now and July, so flights are there for booking on some flights. Perhaps the route you want only flies during busier months?
No, you will be able to book long before 27 March.
What they are saying is that you can only book flights departing before that date, which will mark the end of their winter season. I would assume that the following day will be the beginning of the airline's summer schedule and I would expect those seats to be bookable in the coming weeks.
I am sure that when the airline responds to you, it will be with a date, letting you know when exactly bookings for Summer 2010 can be made.