Moon phase on January 31, 2005

Last Quarter, 61%
🌗 Last Quarter
Monday, January 31, 2005 · at noon (Brasília)
Illumination: 61% Age: 21.1 days Cycle: 72%
Home → Moon phase → January 31, 2005

On Monday, January 31, 2005 the Moon was in its last quarter phase, with 61% of its disk illuminated and an age of 21.1 days since the last new moon. Half of the disk is lit again, on the opposite side from the first quarter. The Moon rises around midnight and is visible in the morning.

Moon data for this date

Moon at noon Brasília time (UTC-3)
Phase🌗 Last Quarter
Illumination61%
Moon age21.1 days
Day of the weekMonday
Last new moonJanuary 10, 2005 at 10:02
Next full moonFebruary 24, 2005 at 01:54 (in 23.6 days)
Next new moonFebruary 8, 2005 at 20:28 (in 8.4 days)

The Moon on the surrounding days

Compare the phase and illumination over the three days before and after. Click a day to open its page.

FriJan 28Waning Gibbous, 88%88%Waning GibbousSatJan 29Waning Gibbous, 80%80%Waning GibbousSunJan 30Waning Gibbous, 71%71%Waning Gibbous
MonJan 31Last Quarter, 61%61%Last Quarter
TueFeb 1Last Quarter, 50%50%Last QuarterWedFeb 2Waning Crescent, 39%39%Waning CrescentThuFeb 3Waning Crescent, 29%29%Waning Crescent

← January 30, 2005 February 1, 2005 →

About the last quarter

Half of the disk is lit again, on the opposite side from the first quarter. The Moon rises around midnight and is visible in the morning. The phase name comes from the Moon's position in its 29.53-day cycle: on January 31, 2005 it had completed 72% of the cycle that began with the new moon on January 10, 2005.

Looking for another date, such as a birthday? Use the Moon phase on the day I was born tool, see the Moon phase today page with the lunar calendar, or find the day of the week of January 31, 2005. For sun times, check sunrise and sunset.

Frequently asked questions

What is the Moon phase on January 31, 2005?

On January 31, 2005 the Moon was in its last quarter phase, with 61% of the disk lit (calculated at noon Brasília time).

How old is the Moon on that date?

The age is the time since the last new moon: 21.1 days of an average 29.53-day cycle.

When is the next full moon after that date?

The next full moon after January 31, 2005 falls on February 24, 2005 at 01:54 Brasília time.

When is the next new moon after that date?

The next new moon after January 31, 2005 falls on February 8, 2005 at 20:28 Brasília time.

How is the Moon phase calculated?

With Jean Meeus's astronomical formulas for the instants of new, quarter and full moon. The age comes from the time since the last new moon and the illumination is (1 − cos(2π × cycle fraction)) / 2.

Is the phase the same everywhere in the world?

Yes, the phase and the illuminated percentage are the same across the planet at any given instant. Only the orientation changes: in the southern hemisphere a waxing Moon is lit on the left, in the northern one on the right.