Blue Moon over North America: At 9:04 pm Eastern Daylight Time on May 31st, the full moon over North America will turn blue.
Not really. But it will be the second full moon of May and, according to folklore, that makes it a Blue Moon. [...]
What about Europe? Because of time zones, this week's full Moon occurs over Europe on June 1st rather than May 31st. In Europe, therefore, it is the month of June which has two full Moons, and a Blue Moon on June 30th. In North America, May has two full Moons and a Blue moon on May 31st.
