Moon Phase Software

Moon tools

Moon Phase Calculator by date

On 2026-10-17, the Moon is first quarter at 12:00 (UTC), 39.1% illuminated.

Start with a date. The default reading uses 12:00 UTC, the middle of that calendar day. Add an exact local time and time zone when you need a precise instant.

Calculation input

Use a named time zone so local clock changes are handled.

Physical lunar phase wheel with a photographed Moon and engraved angle scale

Calculated output

Calculated Moon state

2026-10-17T12:00+00:00[UTC] · UTC

Schematic Moon phase: waxing, 39.10% illuminated at a phase angle of 77.23 degrees. This represents illuminated fraction only, not sky orientation or observer hemisphere.
Schematic illumination only — not sky orientation or observer hemisphere.

Phase at the selected instant

First Quarter

waxing

39.10% illuminated

Lunar age
6.840 days
Phase angle
77.2270°
Selected instant
2026-10-17T12:00+00:00[UTC]
UTC instant
2026-10-17T12:00:00.000Z