The language allowance (LA) is a monetary incentive meant to encourage staff members in the learning and use of the various official languages of the United Nations. The LA recognizes, through a cash payment, the proven ability to function, orally and in writing, in more than one official UN language.
The purpose of the night differential is to compensate staff members performing night-time duty functions. Hours of Night-Time Duty. For staff members stationed in: a) Headquarters duty stations, night-time duty hours are between 6:00 pm and 9:30 a.m. b) Non-headquarters duty stations, night-time duty hours are established by the Resident Representatives (RR), following interagency consultation.