From the FRA forum:
Regular or previous Jura entrants please note: entries for the 2016 race open on 1st December 2015, not at the beginning of March as previously. The race is on Saturday 28th May.
The 2016 race also happens to be a Scottish Hill Runners Championship counter, and is subject to the usual max start line of 250 runners. The earlier entry date is partly to give runners and families a head start on all the Islay whisky and music festival tourists who will be trying to book the same ferries. Entries will not be selected on a strictly first-come-first-served basis.