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 could 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 (GMT) 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.


Obliquity is proud to be a partner with Floris Books in the creation of The Stargazers' Almanac 2012, your monthly guide to the stars and planets.
The Stargazers' Almanac 2012


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Last modified on 13 October 2007
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