29 Days: February, the Menstrual Cycle and the lunar month - all a pure coincidence?

February, the Menstrual Cycle and the lunar month... all have one thing in common: 29 days. A pure coincidence?

February is a rather strange month… the euphoria of the beginning of the year starts to fade and reality starts to kick in. You start questioning all your New Year’s resolutions and start tweaking them to what actually makes sense. Because only now do you realise that the goals you set are not that realistic after all?! The Christmas lights have been turned off and all that remains are the grey days stressed routines, oh and looming tax returns. 

But joy …. February has fewer days! In 2020, only 29 days. March and the start of Spring will come sooner than expected (a little sigh of relief). 

The brevity of February and being brainwashed by the topic of menstruation, it is only natural that the wires connect- sometimes 28, sometimes 29 days - it’s just like the average menstrual cycle. Not just the menstrual cycle but also, as you may know, the lunar month has a cycle length of 29 days.
Mere, but interesting, coincidences?


The fact that February has only 28 / 29 days was a decision made back in the time of the Roman Empire and has a mathematical explanation, combined with a superstition behind it. Want to understand more about how these decisions were made, learn more here.

Jokes and questions are abundant;  “what does happen if you’re born on February 29th?” and “how old are you this year, if your birthday is February 29th?” or “does 2020 have 29 or 28 days?”. In short, the good news is, it is a short month. In Europe, kids have 1 or 2 weeks of holiday during this time, which makes the month fly by even faster. Soon we’ll be heading into March, and the euphoria for spring can start kicking in (can you guess I am a summer lover?). 


Menstrual Cycle

It is said that the average length of a menstrual cycle is 28 or 29 days depending on the source. However, research also shows that the standard deviation is far greater. Only a few lie in the mean value, and it is unique to every individual. It is said that a healthy cycle can vary anything between 21-40 days. Anything deviating too much from this or at the extremes of this range should be looked at with a doctor. 28/29 days is only an estimated average. Deviations are normal. Stress, age, birth control pills and other factors can further influence your cycle length.

The first day of the bleeding is considered the first day of the cycle, and it concludes on the day before the following period. 

The cycle is divided into four phases, that vary in duration:

  • The menstrual phase: 3-8 days
  • The follicular phase: 10-16 days
  • The ovulation phase: 24 hours
  • The luteal phase: around 14 days

The ovulation phase lasts for 24 hours, however, the egg can survive from 12 up to 24 hours after release. Here it is also important to mention that sperm can survive in the uterus for up to 5 days, which can cause in pregnancy even when having unprotected sex outside of the fertile window. 

Lunar Month

It takes 29 days for the Moon to rotate around the earth (counter-clockwise) and it too has 4 phases: 

  • New Moon (when the Moon appears black in the sky and is positioned between the earth and the sun)
  • 1st Quarter
  • Full Moon (when the Moon is to be seen entirely in the sky, and the earth is positioned between the sun and the Moon)
  • Last Quarter

Want to learn about the rotation of the Moon? Check out this video

Although many beliefs exist, that the menstrual cycle and the Moon are synced, research has proven the contrary. A blog post by the cycle tracker Clue, goes in-depth in research and concludes that besides the derivation of the name (the word menstruation is derived from the Latin mensis (month) and the Greek mene (Moon)) there is no real proof that the menstrual cycle and the lunar month are indeed related. 

There are, however, spiritual theories that claim higher sensitivity and female power when the menstrual and the lunar cycle are in sync. A Red Moon being when the period occurs during the same time as the full Moon and the White Moon when having your periods during the new Moon. Alisa Vitti, the writer of the book Woman Code, wrote some tips on how you can sync your cycle to the Moon and make the best out of it. 

Since it is February, why not use the opportunity to try it out?


Even though none of the three topics above has scientific proof of being related to each other, one thing is certain, regardless that periods don’t have the length of a “normal” month, people tend to simplify it and call it a monthly (four week) period of time. 

With that in mind, we simplified your purchasing journey at Mondays. This year we launched the new option in our website to purchase any of our Kits in the form of subscription and have it delivered every 4 or 8 weeks depending on your cycle. Check it out: https://organicmondays.com/pages/gifts

The option of tailor-making your box with the products (tampons, pads and/or pantyliners) that fit best your needs, and choosing your personal cycle length still remains. Create your own personal box now https://organicmondays.com/products/box

You can cancel, pause or skip any of your subscriptions, at any time. And if you are located in the UK or Ireland, use our GBP Website: https://organicmondays.co.uk/

Wishing you all a happy week, a happy February, and a happy cycle.