Mazalogy · Moon and Hebrew time
Follow the Moon through a month, find the next primary phases, and keep their calculated times beside a clear Hebrew-calendar context.
The Moon at one stated instant
14.5%Illuminated disk · %
This reference starts with a fixed, printed UTC instant. Change the UTC date and time, or use now, to calculate another instant on your device.
The dated reference, month samples and source notes remain readable without JavaScript. Enable JavaScript to change the selections and export new calculations.
The dated reference, month samples and source notes remain readable without JavaScript. Enable JavaScript to change the selections and export new calculations.
A month at local noon
UTC · Local noon
Each civil date is sampled at 12:00 in the selected time zone. Read the UTC instant and offset beside each sample; primary phase events are listed at their own calculated times.
Waning gibbous
72.9%
2026-10-01
12:00 UTC
Before evening · Hebrew date20 Tishrei 5787
Waning gibbous
62.2%
2026-10-02
12:00 UTC
Before evening · Hebrew date21 Tishrei 5787
Waning gibbous
50.8%
2026-10-03
12:00 UTC
Before evening · Hebrew date22 Tishrei 5787
Waning crescent
39.4%
2026-10-04
12:00 UTC
Before evening · Hebrew date23 Tishrei 5787
Waning crescent
28.7%
2026-10-05
12:00 UTC
Before evening · Hebrew date24 Tishrei 5787
Waning crescent
19.1%
2026-10-06
12:00 UTC
Before evening · Hebrew date25 Tishrei 5787
Waning crescent
11.2%
2026-10-07
12:00 UTC
Before evening · Hebrew date26 Tishrei 5787
Waning crescent
5.3%
2026-10-08
12:00 UTC
Before evening · Hebrew date27 Tishrei 5787
Waning crescent
1.6%
2026-10-09
12:00 UTC
Before evening · Hebrew date28 Tishrei 5787
Waning crescent
0.1%
2026-10-10
12:00 UTC
Before evening · Hebrew date29 Tishrei 5787
Waxing crescent
0.9%
2026-10-11
12:00 UTC
Before evening · Hebrew date30 Tishrei 5787
Waxing crescent
3.7%
2026-10-12
12:00 UTC
Before evening · Hebrew date1 Cheshvan 5787
Waxing crescent
8.4%
2026-10-13
12:00 UTC
Before evening · Hebrew date2 Cheshvan 5787
Waxing crescent
14.5%
2026-10-14
12:00 UTC
Before evening · Hebrew date3 Cheshvan 5787
Waxing crescent
21.8%
2026-10-15
12:00 UTC
Before evening · Hebrew date4 Cheshvan 5787
Waxing crescent
30.1%
2026-10-16
12:00 UTC
Before evening · Hebrew date5 Cheshvan 5787
Waxing crescent
39.1%
2026-10-17
12:00 UTC
Before evening · Hebrew date6 Cheshvan 5787
Waxing crescent
48.5%
2026-10-18
12:00 UTC
Before evening · Hebrew date7 Cheshvan 5787
Waxing gibbous
58.0%
2026-10-19
12:00 UTC
Before evening · Hebrew date8 Cheshvan 5787
Waxing gibbous
67.4%
2026-10-20
12:00 UTC
Before evening · Hebrew date9 Cheshvan 5787
Waxing gibbous
76.3%
2026-10-21
12:00 UTC
Before evening · Hebrew date10 Cheshvan 5787
Waxing gibbous
84.4%
2026-10-22
12:00 UTC
Before evening · Hebrew date11 Cheshvan 5787
Waxing gibbous
91.2%
2026-10-23
12:00 UTC
Before evening · Hebrew date12 Cheshvan 5787
Waxing gibbous
96.3%
2026-10-24
12:00 UTC
Before evening · Hebrew date13 Cheshvan 5787
Waxing gibbous
99.3%
2026-10-25
12:00 UTC
Before evening · Hebrew date14 Cheshvan 5787
Waning gibbous
99.7%
2026-10-26
12:00 UTC
Before evening · Hebrew date15 Cheshvan 5787
Waning gibbous
97.4%
2026-10-27
12:00 UTC
Before evening · Hebrew date16 Cheshvan 5787
Waning gibbous
92.4%
2026-10-28
12:00 UTC
Before evening · Hebrew date17 Cheshvan 5787
Waning gibbous
85.1%
2026-10-29
12:00 UTC
Before evening · Hebrew date18 Cheshvan 5787
Waning gibbous
75.8%
2026-10-30
12:00 UTC
Before evening · Hebrew date19 Cheshvan 5787
Waning gibbous
65.3%
2026-10-31
12:00 UTC
Before evening · Hebrew date20 Cheshvan 5787
| Phase | Local date and time | Calculated instant · UTC | Before evening · Hebrew date | After evening · Hebrew date |
|---|---|---|---|---|
| Last quarter | 2026-10-03 13:25 +00:00 | 22 Tishrei 5787 | 23 Tishrei 5787 | |
| New moon | 2026-10-10 15:50 +00:00 | 29 Tishrei 5787 | 30 Tishrei 5787 | |
| First quarter | 2026-10-18 16:13 +00:00 | 7 Cheshvan 5787 | 8 Cheshvan 5787 | |
| Full moon | 2026-10-26 04:12 +00:00 | 15 Cheshvan 5787 | 16 Cheshvan 5787 |
An astronomical new moon is a conjunction event. Rosh Chodesh follows the fixed Hebrew calendar; the traditional molad is a mean-motion calculation. The two Hebrew dates shown are candidates before and after the evening boundary. No location or sunset is calculated here.
Source
Sefer Yetzirah, Gra version, 4:8 links the Moon with Bet and wisdom. Read this fixed textual association beside the changing phase.
An astronomical new moon is a conjunction event. Rosh Chodesh follows the fixed Hebrew calendar; the traditional molad is a mean-motion calculation. The two Hebrew dates shown are candidates before and after the evening boundary. No location or sunset is calculated here.
This is one named source record, kept constant through the lunar cycle. The Bet reference and version comparison preserve the wording and edition.
The drawings are original illumination schematics. They do not show an observer’s sky orientation or predict crescent visibility.
Primary events use the Moon–Sun difference in geocentric ecliptic longitude: 0° for new moon, 90° for first quarter, 180° for full moon and 270° for last quarter. Between these events, waxing or waning crescent and gibbous labels follow direction and the calculated illuminated fraction. A primary label belongs to the event, rather than a broad stretch of days.
Astronomy Engine 2.1.19 calculates locally. Event times are displayed to the minute. Independent checks of all 100 published USNO events for 2024 and 2026 used a 120-second comparison tolerance; the largest observed difference was 79.496 seconds. USNO publishes UT1 to the minute, while the calculations are expressed in UTC. This check covers those two years and does not promise second-level accuracy; computed seconds in exports retain model output, not an accuracy claim.
The selected time zone determines civil dates and local-noon sampling. A historical clock change can remove a noon or repeat it. A missing noon has no sample. A repeated noon uses the earlier occurrence, with both possible UTC instants retained. The event list uses actual phase instants, independently of these daily samples.
Hebrew-date candidates use the selected zone’s civil date: one before the evening boundary and the following Hebrew date after it. The tool does not decide which candidate applies at an astronomical instant. Read the existing Rosh Chodesh article for the calendar distinction and use the calendar for its fixed month dates.
Prepared by Mazalogy with AI assistance and source checks. No qualified scholarly or native-language review is claimed.
The link retains the selected UTC instant, calendar month and time zone.
Mazalogy. “Moon phases & Hebrew calendar context.” 2026-10-14. Reference instant: 2026-10-14T12:00:00.000Z. Gregorian calendar month: 2026-10; Time zone: UTC. https://mazalogy.com/en/moon-phases/