Between 9:00 p.m. and 04:00 a.m, the visiting Bucharesteres could watch the skies through telescopes and make astronomical observations, watch a planetarium show displaying the sky visible on that night, and also attend a presentation of different types of astronomical instruments. The International Astronomy Day is celebrated since 1973 on a Saturday in either April or May, when the first-quarter Moon is visible. This event is preceded by the celebration of the Global Astronomy Month – GAM.
According to the site of the Bucharest Astronomy Observatory, this move began in California (US) 37 years ago, when amateur astronomer Doug Berger decided to organize astronomical observation sessions for the broad public through the local club Astronomical Association of Northern California’s whose chair he was. The first club that organized a similar event in Romania on Astronomy Day was the Romanian Astronomical Meteor Society (SARM), in 2003.