to the congregations of God

Members discussing and researching current issues facing the congregations of God today

Jewish Calendar Accuracy Test

The Jewish calendar’s calculations attempt to follow the average length of the new moon. But the difference between the Jewish calendar’s average length of a new moon, and the actual length of the new moon is off by a very small amount.

The most accurate difference is -.57 seconds (Dr. Irv Bromberg, COGWA, Jewdaism 101). The approximate value of 3/5 of second is -.6 seconds (Approx. Dr. Irv Bromberg). 2 Millionths of a month is -.17 seconds (Avraham Yaakov Finkel). How much of a difference do any of these make in calculating the dates of the holy days using the Jewish calendar?

Jewish calendar calculations difference (in seconds)

Year range - BCE: ({{total_years}} years)



With a {{ (molad_diff > Math.floor(molad_diff)) ? molad_diff.toFixed(2):molad_diff }} second correction to the calculation of the Jewish calendar, {{errors_percentage}}% of the holy days from {{start_year}} to {{end_year}} ({{total_years}} years) are on the wrong date.

Results summary:
Total on wrong date: {{i_errors}}
Off by 1 day: {{errors_off_by_1}}
Off by 2 days: {{errors_off_by_2}}
Off by 3 or more days: {{errors_off_by_3_or_more}}

Earliest month:{{month_names[month_earliest]}}, Latest month: {{month_names[month_latest]}}

(days diff.)
(Jewish Molad)
(corrected by {{molad_diff}} sec.)
{{date.days_diff}} * {{date.tishri1_source_month}}/{{date.tishri1_source_day}}/{{date.gregorian_year}} {{date.tishri1_month}}/{{date.tishri1_day}}/{{date.gregorian_year}}

* This year has a difference between the inaccurate measurements of the average cycle of the new moon conjunction of the Jewish calendar compared to the corrected measurements.