Blue Moon - The Blue Moon of 2007

Our Blue Moon Calculator says that in 2007, there is a Blue Moon in June. You may have heard or read reports which said that the Blue Moon really occurs in May. Who is right?

Well, you can see Blue Moons in May, June or even July, but it depends where in the world you live.

Let's start with the basic astronomical facts. The four Full Moons in May, June and July 2007 are as follows:

2 May	at	10:09 GMT
1 June	at	01:04 GMT
30 June	at	13:49 GMT
30 July	at	00:48 GMT

These dates and times have been calculated rigorously using the same methods as those employed by the United States Naval Observatory and by Her Majesty's Nautical Almanac Office. They are given in Greenwich Mean Time which is the standard time zone used by astronomers worldwide.

Notice that the second Full Moon in the list occurs early in the morning of 1 June. Changing the time zone by two hours or more to the west of Greenwich changes the month in which the Full Moon falls. In the Americas, the Full Moon is on the evening of 31 May, not 1 June.

Here are those four Full Moons again, but with the dates and times adjusted for several major time zones around the world. For each time zone, the two Full Moons which fall in the same calendar month are highlighted.

City	Time zone	Full Moon 1	Full Moon 2	Full Moon 3	Full Moon 4
Places East of Greenwich
Auckland	GMT + 12 hours	May 2 22:09	June 1 13:04	July 1 01:49	July 30 12:48
Sydney	GMT + 10 hours	May 2 20:09	June 1 11:04	June 30 23:49	July 30 10:48
Tokyo	GMT + 9 hours	May 2 19:09	June 1 10:04	June 30 22:49	July 30 09:48
Moscow¹	GMT + 4 hours	May 2 14:09	June 1 05:04	June 30 17:49	July 30 04:48
Riyadh	GMT + 3 hours	May 2 13:09	June 1 04:04	June 30 16:49	July 30 03:48
The Greenwich Meridian
London¹	GMT + 1 hour	May 2 11:09	June 1 02:04	June 30 14:49	July 30 01:48
Places West of Greenwich
Buenos Aires	GMT - 3 hours	May 2 07:09	May 31 22:04	June 30 10:49	July 29 21:48
New York¹	GMT - 4 hours	May 2 06:09	May 31 21:04	June 30 09:49	July 29 20:48
Chicago¹	GMT - 5 hours	May 2 05:09	May 31 20:04	June 30 08:49	July 29 19:48
Los Angeles¹	GMT - 7 hours	May 2 03:09	May 31 18:04	June 30 06:49	July 29 17:48
Anchorage, Alaska¹	GMT - 8 hours	May 2 02:09	May 31 17:04	June 30 05:49	July 29 16:48
Hawaii	GMT - 10 hours	May 2 00:09	May 31 15:04	June 30 03:49	July 29 14:48
¹ These places observe daylight saving time in May, June and July.

As you can see, Europe, Africa, Asia and Australia see the Blue Moon on 30 June, whilst the Americas see it on 31 May, and New Zealand must wait until 30 July to see its Blue Moon.

Once in a Blue Moon

The Blue Moon of 2007