Moon Calendar · January 2021
Daily moon phases, illumination, and key lunar dates.
January lunar highlights
A clearer way to see moon.
Follow the lunar cycle through a calm monthly visual.
The moon calendar estimates lunar age and illumination for every date, so neighboring days progress through the cycle instead of repeating one fixed icon.
It is suitable for general planning and visual comparison. Local time zones can shift the civil date of an exact lunar phase, and the calculation is not intended for navigation.
Read our data and calculation methods for coverage and accuracy limits. If a date or result looks wrong, report a calendar error.
Good to know
Why can another source show a different phase date?
Exact phase times are global instants; converting them into local dates can move the label by one day.
Is illumination the same as lunar age?
No. Lunar age measures time in the cycle, while illumination estimates the visible sunlit fraction.