On 20 December 2017, the United Nations General Assembly adopted a resolution declaring 20 May of each year as World Bee Day.

The resolution specifically took into account the thematic Assessment Report on Pollinators, Pollination and Food Production, released in February 2016 by IPBES, and also the thirteenth meeting of the Conference of the Parties to the Convention on Biological Diversity, which took place in Cancun, Mexico, from 4 to 17 December 2016, and its decision XIII/15 on the implications of the IPBES assessment for the work of the Convention https://www.worldbeeday.org/files/declaration/RESOLUTION_L32_World_Bee_Day.pdf  

In 2015, the Republic of Slovenia, at the initiative of the Slovenian Beekeepers' Association, began procedures at the Food and Agriculture Organization of the United Nations (FAO) for the declaration of World Bee Day and to propose a resolution underlining the importance of bees and other pollinators. The initiative was endorsed by the Conference of the Food and Agriculture Organization of the United Nations at its 40th Session in Rome on 7 July 2017; and the procedure was successfully concluded today with the unanimous adoption of the World Bee Day Resolution by the UN General Assembly https://www.worldbeeday.org/en/events/latest-news/36-20-may-declared-as-world-bee-day.html

See webcast of  the proceedings (The adoption of the resolution is at 1:17:42): http://webtv.un.org/watch/general-assembly-74th-plenary-meeting-72nd-session/5686391341001/. You can read the proceedings of the session here https://www.un.org/press/en/2017/ga11994.doc.htm