Hardly buried
FLEXI fares - For travel within the next 120 days, departing from the UK to any easyJet destination. Flexi ticket allows unlimited date changes in a fixed 4 week period, subject to availability, for changes made at least 2 hours before original departure.
http://www.easyjet.com/en/business/flexi-fares
Unlimited free date changes to your flight within a 4 week period. From 1 week before to 3 weeks after the original travel date. Fares are available to book 120 days from the current date.