On July 10, 2014, the Universal House of Justice announced three decisions regarding the Badi` (Bahai) calendar, which will affect the dates of Feasts and Holy Days. Naw Ruz will usually fall on March 20th, which means that all the Feast days will be one day earlier, and the births of the Bab and of Baha'u'llah will be celebrated on two consecutive days in the Autumn. The changes take effect from the next Bahai New Year, from sunset on March 20, 2015.
The definitive tables showing the new dates have not yet been released, but there is a preliminary discussion here :
The letter in which the Universal House of Justice announced the changes is online here :