Two biodynamic calendars can give different answers because they use different rules, time zones or ways of labeling a day. Here is how to tell those differences apart.
It started with an Instagram message
A friend messaged me on Instagram asking why Moonvine and another biodynamic calendar disagreed. It was a fair question: if both follow the Moon, shouldn’t they show the same thing?
That question sent me back through Moonvine’s calculations. The review led to changes in how Moonvine handles traditional day categories and pauses, bringing its recommendations closer to the established sowing-calendar tradition. Changing the clock alone would not have resolved the differences.
Moonvine remains an independent interpretation. Agreement with another calendar is a useful consistency check; it does not establish that a day type changes how wine tastes or plants grow.
1. The same sky, different calendar conventions
A Moon phase calendar, an equal-sign zodiac calendar and a biodynamic calendar need not be calculating the same thing. Waxing and waning describe the phase. Zodiac systems divide the Moon’s path into sectors, and equal 30° signs differ from unequal sectors used in some biodynamic traditions. Even calendars using unequal sectors can choose different boundaries.
The base fruit, flower, leaf or root category may also be interrupted by a traditional pause or changed by another influence. Which events count, how long their windows last and which rule takes priority can all change the result. A constellation label alone therefore does not fully explain a recommendation.
The Floris Books calendar FAQ describes lunar, solar and planetary influences and unfavorable periods. It is a useful description of that tradition, rather than a complete numerical specification for every calendar.
2. The same transition, different local dates
In Moonvine’s current calculation, a Flower period changes to a Leaf period at 01:00 UTC on 1 November 2026. Here is that single instant on three clocks, with the daylight-saving rules for that date applied:
| Time zone | Flower → Leaf transition |
|---|---|
| UTC | |
| New York local time · America/New_York | |
| Paris local time · Europe/Paris |
In New York, the change belongs to the evening of 31 October; in Paris, it belongs to the early hours of 1 November. These are the same transition. This example uses Moonvine’s calculation throughout, rather than comparing two publishers’ predictions.
A fixed offset such as “New York is always UTC−5” would give the wrong answer here: New York is still on UTC−4 at this instant. Use the calendar’s named time zone and the offset for the date being compared.
3. A daily label and a tasting-time answer can differ
Consider 31 October in New York in that example. Flower occupies most of the local day, but Leaf begins at 21:00. A calendar choosing the longest category could label the date Flower; an exact-time check at 22:00 would say Leaf. That is a difference in summary convention, even when both use the same underlying timeline.
Daily summaries might instead use the category at noon, the start of the day or every category present. Before comparing colored squares, check what each square means.
A useful order for checking a disagreement
- Choose one exact date and time, including the year.
- Set both calendars to the same named time zone and check daylight saving.
- Open the hourly detail rather than comparing a daily headline.
- Check whether a pause or another traditional influence overrides the base category.
- If the answers still differ, read each method. Record the difference rather than assuming either calendar is wrong.
What this means when using Moonvine
For a particular glass or gardening task, use the period covering the actual local time. Moonvine calculates its recommendations on your device and shows the same underlying timeline across time zones. See our calculation guide for the method, today’s timeline for the current periods, and the evidence guide for what calendar agreement can and cannot tell us.
Questions
Is a disagreement always a time-zone problem?
No. A time-zone change shifts the displayed clock and sometimes the local date; it cannot reconcile different category rules or different pause lengths.
Does Moonvine reproduce the official Maria Thun calendar?
No. Moonvine is independently implemented and is not the official published calendar. Its recommendations can differ.
Does a Fruit Day last from midnight to midnight?
Not necessarily. Fruit, flower, leaf and root periods can start or end during a local day, and traditional pauses can interrupt them.
