Moon ExactlyDaily lunar detail
January 1991 Moon Calendar
The month opens with a Full Moon and closes with a Full Moon. It contains 4 exact major phase events.
Icons use the common Northern Hemisphere convention: waxing light on the right, waning light on the left. Your sky may appear rotated at other latitudes.
The lunar story of January 1991
New Moon occurs January 15, 1991. Full Moon occurs January 30, 1991. The first major event is Last Quarter on January 7, 1991, and the month progresses from 99% to 98% illumination at noon UTC on its boundary dates.
Choosing a day
Select any Moon to open its precise phase angle, illuminated fraction, elapsed age since New Moon, trend, and neighboring event. Date result pages remain shareable but are excluded from search indexing.
Questions, answered
Frequently asked questions
What time are daily phases calculated?
12:00 UTC, chosen deliberately to keep date-only selections stable worldwide.
Why can a local phase event fall on another date?
An event near 00:00 UTC may occur on the previous local date west of Greenwich or the next local date east of it.
Do the icons show sky orientation?
They use a Northern Hemisphere convention; actual orientation rotates with latitude and viewing angle.