Why don't the phases of the moon occur on the same day each month?

The different phases of the moon do not happen on the same days each month because the moon's orbit around the Earth does not take exactly one month. The cycle of the phases from new moon to new moon, takes 29 and 1/2 days. Because of this, moon phases can happen anywhere during the months.

Blue Moon - 31 August 2012
The second full moon occurring within a calendar month is called a Blue Moon. The last blue moon was seen on 31 December 2009. Far from being a rare event this phenomenon occurs once every three years on average. The next one will occur in August 2012.

Who finds this page useful?

Kayaker
As a kayaker in the desert southwest, I usually go kayaking before the sun comes up, since this is the coolest part of the day - I user your moon calendar to pick the most well-lit times (mostly full moon) - thanks for your great page!

Student
I use your moon calendar to help me record the phases of the moon for my homework when it is too cloudy to see the moon.

Fishermen
The moon phases are a very real factor in the feeding patterns of fish. I have used your moon phases to help me find out about the best fishing times. Sea fish feed better on a full moon, a great website thanks.

The phases of the moon are important to freshwater anglers as well. The new moon and full moon phases are particularly important as the two or three days following these two phases will result in more fish activity.

Gardener
I used your moon calendar to know when the full moon was as it is the best time to plant. In the olden days, watching the moon was the only way to know when it was time to plant.

Photographer
We are having a discussion in a photography forum about the best settings to photograph the full moon, so your moon data is particularly helpful in planning for this. Thanks.

Traveller
Thanks for the moon phases as I now know 2 Nov 09 is the Loi Kratong festival in Thailand which is going to be the highlight of my holiday there

Moth Collector
Thanks for the information on Moon phases. I use it, in conjunction with the weather forecast for my area, to decide the best nights to put out my moth trap. The best nights are overcast or dark nights, so I need to know how bright the moon is going to be.

Wedding DJ
I found your full moon phases planner really useful for summer weddings, if there is likely to be a full moon, and I have a marquee or rural disco, I can moderate the light leakage so people outside can really enjoy the evening.

Pagan
As a pagan I use the phases as a source of energies at different times.