New Moon

New Moon Tools

The first visible crescent of the new moon marks the beginning of the Biblical month.  The spring and fall holy days (as well as each new month) are determined by this signal in the sky.

And YHWH said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years (Gen 1:14 KJV)

signs = H226 =  a signal, as a flag, beacon, monument, mark

The information on this page assumes the first visible crescent of the new moon should be declared from Jerusalem and only Jerusalem .

For out of Zion shall go forth the law, and the word of YHWH from Jerusalem (Isa 2:3 KJV).

The tools described below will assist the user in determining the probable date the visible crescent is most likely to appear, however whenever possible, visible confirmation is always preferable.

Current Month Isolation Graph

The following link shows the global visibility of the projected new moon crescent shadow for the 3 day lunation period at the beginning of the current month.  The graph is updated with new data prior to the next months new moon cycle.

The color scheme indicates the probability of sighting the new moon crescent from any worldwide geographic location.  An archive of previous months data is available dating back to 2005.

Current New Moon Isolation Graph

An email signup notification for next months new moon dates is available from the website.

Positive and negative sighting reports can also be made from this website.

Reporting Web Sites
These links define the new moon as the first visible crescent.  (North American declarations)  (Jerusalem declarations)  (Worldwide declarations)

The following Bible Calendar software programs run on Windows (including Windows 10).  Both programs run offline, no Internet connection is required after initial download.  Both programs produce consistent very accurate results and can be used to determine existing, future and previous new moon crescents dating back to 1 CE.  Both programs use Jerusalem as the default observation location, however any geographic longitude/latitude coordinates may be used.  These are effective tools for research and predicting future 1st visible crescent moon dates.

Israeli New Moon Society
LunaCal 4.0
Courtesy Roy Hoffman

Central Highlands Christian Publications
PO Box 236, Creswick, Vic. 3363 Australia
Calculated Bible Calendar for Windows

Note:  Both programs are installed at this location and run error free, however this web site makes no guarantee to the stability of these programs on your computer.  Always verify downloads to be free of virus and/or malware infection.  Download and install at your own risk.


You shall know the truth, and the truth shall make you free – John 8:32