February 26

The exchanging of presents among believers or the giving of gifts to children is not an integral part of any of our nine Bahá'í Holy Days. There is no prohibition against it, and it is, as you say, a custom among Persian believers such as the Bahá'í to whom you spoke, to exchange gifts at Naw-Ruz. 
- The Universal House of Justice  (From a letter written on behalf of the Universal House of Justice to an individual believer, January 18, 1982; compilation: ‘Lights of Guidance’)