Well, you could have seen Blue Moons in all three months, but it depended where in the world you lived.
Let's start with the basic astronomical facts. The last four Full Moons in 2001 are as follows:
| 2 October | at | 13:49 GMT |
| 1 November | at | 05:41 GMT |
| 30 November | at | 20:49 GMT |
| 30 December | at | 10:40 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 occurred just 5 hours and 41 minutes after the start of November, and the third Full Moon was just 3 hours and 11 minutes before the end of the month. In either case, changing the time zone by only a few hours changed the month in which the Full Moon fell. In Chicago and places further west, there was a Full Moon on Halloween in 2001.
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 fell in the same calendar month are highlighted. We have ignored daylight saving time because it had no effect on the dates of the Full Moons.
| City | Time zone | Full Moon 1 | Full Moon 2 | Full Moon 3 | Full Moon 4 |
|---|---|---|---|---|---|
| Places East of Greenwich | |||||
| Sydney | GMT + 11 hours | Oct. 3 00:49 |
Nov. 1 16:41 |
Dec. 1 07:49 |
Dec. 30 21:40 |
| Tokyo | GMT + 9 hours | Oct. 2 22:49 |
Nov. 1 14:41 |
Dec. 1 05:49 |
Dec. 30 19:40 |
| Islamabad (Pakistan) |
GMT + 5 hours | Oct. 2 18:49 |
Nov. 1 10:41 |
Dec. 1 01:49 |
Dec. 30 15:40 |
| Moscow | GMT + 3 hours | Oct. 2 16:49 |
Nov. 1 08:41 |
Nov. 30 23:49 |
Dec. 30 13:40 |
| The Greenwich Meridian | |||||
| London | GMT | Oct. 2 13:49 |
Nov. 1 05:41 |
Nov. 30 20:49 |
Dec. 30 10:40 |
| Places West of Greenwich | |||||
| New York | GMT - 5 hours | Oct. 2 08:49 |
Nov. 1 00:41 |
Nov. 30 15:49 |
Dec. 30 05:40 |
| Chicago | GMT - 6 hours | Oct. 2 07:49 |
Oct. 31 23:41 |
Nov. 30 14:49 |
Dec. 30 04:40 |
| Los Angeles | GMT - 8 hours | Oct. 2 05:49 |
Oct. 31 21:41 |
Nov. 30 12:49 |
Dec. 30 02:40 |
| Hawaii | GMT - 10 hours | Oct. 2 03:49 |
Oct. 31 19:41 |
Nov. 30 10:49 |
Dec. 30 00:40 |
As you can see, places in time zones between New York and Moscow saw two Full Moons in November.
However, if you were in Chicago's time zone, or further west, then November had only one Full Moon. Instead, there are two Full Moons in October, and the Blue Moon fell on Halloween.
Likewise, if you were further east than Moscow's time zone, both October and November had only one Full Moon each, and it was December which had two.
Copyright © 1995-2007 by David Harper and Lynne Marie Stockman