Your fertile days are more than your cycle

According to the moon phase method, they are largely influenced by something else: the moon under which you were born. I calculate this deeply personal rhythm for you and show the exact days when your fertile windows return.

Discover my fertile days What most people overlook

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The usual approaches

Almost every method counts only the cycle. That is only half the story.

Anyone trying to conceive knows the usual ways of finding the right time. They all revolve around the monthly cycle. Each can be valuable, yet many couples still wait month after month.

  • Calendar & cycle calculator Counts the days from your last period. Quick, but only a statistical average that can miss the mark when cycles vary.
  • Basal temperature Shows ovulation through a small temperature rise. Useful, but only afterwards, when the best moment may have passed.
  • Cervical mucus Can indicate fertile days in advance when cervical mucus becomes clear and stretchy. Requires daily observation and practice.
  • Ovulation test Measures the hormone surge that precedes ovulation by about a day. Precise, but with a short window and ongoing strip costs.
  • Symptothermal method Combines temperature and cervical mucus for careful self-observation. It must be tracked daily over several months.
  • Cycle apps Convenient on a phone, but most simply project the calendar and estimate rather than reading signs from your body.

All these approaches focus on the same point: your monthly cycle.

Yet all these methods overlook something important.

Dr Eugen Jonas described a second, deeply personal rhythm that these methods overlook and that had been largely forgotten. From his evaluation of thousands of women, he proposed a surprising ratio:

85%
of receptiveness, according to Dr Jonas, depends on your personal lunar rhythm, while only 15 per cent depends on the familiar monthly cycle.

I make visible the personal rhythm that none of the methods above takes into account.

Your second rhythm

This second rhythm belongs to you alone

It begins at the moment you are born and accompanies you throughout your life. For a woman trying to conceive, it is considered independent of the monthly cycle. This is how it works.

01

A rhythm born with you

When you were born, the Sun and Moon formed an angle unique to that moment. Whenever this angle returns, roughly every 29 days, the method identifies a fertile window, independently of where you are in your monthly cycle.

02

A few days that belong to both of you

A window lasts about three days and begins shortly before your moon returns. There is no need to watch the clock: every shared moment during these days counts. No countdown, no pressure.

03

As unique as your birthday

Because these days are derived from your own birth, no other woman has exactly the same pattern. You will not find it in a printed moon calendar, only in your own. Your partner's date of birth is not used. I calculate the windows by date in your time zone, including daylight saving time.

Your calculation

Find your fertile days free

Enter your date of birth and immediately see which days in the last six months were considered particularly fertile. Your birth moon reveals them at no cost. You can then unlock the next twelve months.

All details refer to you as the woman trying to conceive: your date, time and place of birth.

My date of birth *

* This is how I calculate your birth moon phase. Only your own date of birth is used, not your partner's.

My time of birth

Even an approximate time of day improves the calculation. Without one, I use 12:00 noon.

My birthplace

This determines the time zone of your birth. Daylight saving time is applied automatically.

My current location

Your results are shown in the local time of your current location.

My name (optional)

Your six-month retrospective: free

The moon at your birth

Edit details

Your retrospective: fertile days from the last six months free

How to read your opportunities

  • Each opportunity is a window of about three days around the best day. It opens shortly before your moon returns and closes afterwards.
  • There is no single hour to aim for: every shared moment within the window counts. This leaves room and calm, without pressure.
  • Compare the dates calmly with your own memories from recent months.
  • This retrospective is my gift to you. You can order your future opportunities as a personal overview below.

Your opportunities in the last six months at a glance

Fertile window Best opportunity Today

Select a marked day to jump to the matching opportunity.

Now look ahead

29 €one-off, no subscription

Delivered by email · Printable PDF · With expected birth periods

View sample PDF

How it works

From your birth to your fertile days

1

Enter your birth details

Your date of birth, approximate birth time and birthplace reveal the moon under which you were born, the starting point for your personal dates.

2

View your free retrospective

You immediately see which days in the last six months were considered particularly fertile. Compare them calmly with what you noticed yourself.

3

Order future opportunities

You receive your opportunities for the next twelve months as a carefully designed PDF by email, a shared companion while trying to conceive.

Your year ahead
My opportunities
12 months · personally calculated

Your path ahead

A full year of your fertile days at a glance

Every day on which your moon returns in the next twelve months, calculated solely from your own birth details. A calm, clear overview for both of you.

  • Every opportunity with its gentle window of about three days
  • For every opportunity: expected birth period and zodiac sign
  • A boy or girl tendency for every opportunity
  • Twelve months ahead, in your local time with automatic daylight saving
  • Carefully designed for printing or viewing on your phone
  • Delivered conveniently by email
29 €one-off, no subscription

View the sample PDF: this is what your overview looks like

The story behind it

People have looked to the moon for generations

The moon accompanies the night, drives the tides and has long represented change, rhythm and return. Many traditional cultures observed it closely in sowing and harvest, sleep and birth, and the female cycle. It was seen not only as a celestial body but as part of a wider natural rhythm.

In 1956, Dr Eugen Jonas revisited these old observations. He said he evaluated thousands of women and believed the moon phase at birth revealed a second fertility rhythm, the 85 per cent mentioned above.

I have made this method calculable with modern astronomical data: testable, consistent and individual to each woman.

Good to know

Frequently asked questions

What is the moon phase method?

According to the moon phase method, the angle between the Sun and Moon at the time of your birth returns in every lunar cycle. The method considers this a particularly receptive window. I calculate these dates astronomically from precise ephemeris data.

I do not know my time of birth. Can I still use the calculator?

Yes. Without a time, I calculate with 12:00 noon, so the difference is at most about half a day. Even an approximate time of day, such as evening, makes your dates much more precise. It is worth checking your birth certificate.

Does my partner's date of birth matter?

No. The calculation only uses your own birth details: your date, time and place of birth. The prospective father's details are not part of the calculation.

Does this calculation replace medical advice?

No. The moon phase method does not promise a pregnancy. Please speak to a doctor about fertility, cycle or health questions.

What do I receive when I unlock the calendar for €29?

All your opportunities for the next twelve months, each with its window and expected birth period, in a carefully designed PDF delivered by email. One-off payment, no subscription.

About German
Portrait of German Besler in the Allgäu mountains

German Besler

Spiritual healer · Hinterstein in the Allgäu

German lives and works in Hinterstein, a mountain village in the Allgäu. His work is spiritual and energetic, not medical: calm attention to what may lie beneath the visible, with both feet on the ground.

The idea of the birth moon stayed with him. He made the method calculable with current astronomical data and checked it against confirmed reference cases so that the personal windows can be found consistently.

Learn more about German and his work at germanbesler.de

Your first step

Find the days that matter

In less than a minute, see your fertile days from the last six months. Free, without registration, just for you.

Discover my fertile days