Oddly, we are celebrating the Jubilee from June 2nd, the date of the coronation 59 years ago,but in the year which marks 60 years of the reign. Presumably nobody thought it wise to use the date of the accession, which was in February, because the weather isn't good in February; the same thinking which gives us the official birthday of a monarch, regardless of the actual birthday. The official birthday was created because the then King's real birthday was at a cold time of year and not ideal for parades and such.