Observational
lunisolar
Watch the lunar cycle and keep the festivals in their biblical seasons.
- Months
- Lunar, usually 29 or 30 days.
- Year
- An extra month when needed.
- Tradeoff
- Some dates need confirmation closer to the observance.
Scripture · Understanding · Faithfulness
At Moedim Made Easy, we're moving to the Observational Lunisolar Calendar-the approach we currently believe best fits Scripture and the historical evidence.
Start with the basics ↓New to biblical calendars? You don't need to know the terminology to begin.
A change in our approach
We previously followed the fixed rabbinic calendar, commonly called Hillel, for the sake of unity. As we've studied, we've become more persuaded by an observational approach. Unity matters, but it cannot decide what is true.
We're explaining our decision openly, while continuing to examine our conclusions.
Let's make the word simple
Lunar refers to the moon. Solar refers to the sun. A lunisolar calendar follows lunar months while keeping the year aligned with the seasons.
Months follow the moon's cycle.
Usually 29 or 30 days.
The year stays in step
with the seasons.
Lunar months within
a seasonal year.
Twelve lunar months are about 354 days. A seasonal year is about 365 days. Without a correction, the months would move through the seasons.
Simplified teaching diagram. The method for choosing leap months is a separate question.
Three approaches worth understanding
The disagreement is about how dates are established. Hillel is also lunisolar. It uses a fixed calculation instead of declaring each month from a sighting.
Watch the lunar cycle and keep the festivals in their biblical seasons.
A shared, predictable calendar with lunar months and a seasonal year.
A 364-day pattern built around complete weeks and recurring festival weekdays.
The overlap: observational and Hillel calendars belong to the same lunar-and-seasonal family. The 364-day model organizes its months differently.
For example, Torah places Passover on the 14th day of the first month. The question is how to identify that month's beginning.
Different starting dates can place the same feast on different dates on your everyday calendar. See Exodus 12:1-6.
Why we find it more persuasive
Torah places Passover in the month of Aviv and gives the feasts numbered dates. We believe lunar months within the agricultural seasons make the best sense of that framework.
Philo and Josephus describe lunar festival timing. Early rabbinic accounts also preserve month declarations based on moon witnesses. Taken together, this supports an observational lunar tradition, without proving every detail of a modern method.
Historical evidence: Philo · Josephus · Mishnah Rosh Hashanah 2:6-7 ↓
We do not give an interpretation extra authority simply because it is rabbinic-or because it opposes the rabbis. We test each argument against Scripture, giving primary weight to Torah and the Gospels.
We prefer observation over treating the later fixed rules as binding. Our own observation rules must also be explained and examined.
Torah gives festival dates and seasons, but not a complete formula resolving every calendar question. This is our best-supported conclusion, not a claim that every detail is beyond question.
Why we are keeping the discussion open
We recognize that possibility. The 364-day tradition has genuine ancient roots and deserves serious study. At present, however, we do not believe it presents the stronger argument.
That difference requires a correction over time. Modern advocates propose solutions, including extra weeks. The open question is which correction was used anciently-not whether corrections are inherently wrong. Lunisolar calendars need corrections, too.
What this means for your family
An observational calendar can require more flexibility. Our date guidance will distinguish advance planning estimates from confirmed observances.
A forecast can help you plan meals, activities, and time away. It should be clearly labeled when observation may still affect the date.
A date confirmed under the observation method we adopt. We will explain the evidence and method behind the dates we share.
A calendar change does not reset the weekly Sabbath. The monthly cycle and the ongoing seven-day week are separate.
A few questions you may have
Shared dates have real value, and that is why we previously followed Hillel. But when our study leads us to believe another approach is more faithful, agreement alone cannot settle the question. We can explain our conviction and still treat people who disagree with respect.
No. We do not consider lunar-reset Sabbaths, full-moon month beginnings, or permanently uncorrected 360- or 364-day years likely models of the original biblical calendar.
Other calculated lunisolar and Samaritan methods are not the approach we are adopting. They are not all equally improbable. Karaite observational methods can overlap with our chosen calendar family.
We cannot claim that. We consider the lunar-and-seasonal family the most plausible broad reconstruction, but Moses' precise calendar procedure is not recoverable with certainty. Our strongest direct historical evidence comes from the later Second Temple period.
Not necessarily. Observational groups differ over reference location, accepted sightings, and how to identify the beginning of the year. Those details must be stated clearly; the name "observational" does not settle them.
No. Choosing the calendar family does not automatically settle the interpretation of the Sabbath used to begin the count in Leviticus 23. The counting method needs its own explanation.
You are welcome to keep learning with us. This page explains our decision about timing; it does not claim to know another believer's heart. We encourage you to read the passages, weigh the evidence, and ask honest questions.
Yes, if stronger scriptural and historical evidence warrants it. Putting truth first includes being willing to correct our own understanding.
Keep learning with us
You do not need to master every calendar debate before learning what God's feasts teach. Begin with Scripture, ask questions, and take the next step.
Explore the feast days →The page keeps the explanation short. These sources let you examine the reasoning yourself. Historical witnesses inform our study; they do not replace Scripture.
We encourage you to read the evidence, compare the arguments, and keep studying with us.