Daysy does not equate contraception! We help you to determine exactly WHEN you have to use contraception.

Calculating fertile days with the calendar method?


Discover the advantages of Daysy and the practical fertility app DaysyView!

Have you settled for natural family planning and would like to use the calendar method for birth control? Then be advised that this method is very unsafe and strictly not recommended by experts. Why? Because your cycle can change at any time: Just a little bit of stress at work or a small flu can lead to errors in your calculation without you even noticing it. Calculating your fertile days with the calendar method basically only makes sense when you want to get pregnant anyway and don’t care how quickly you conceive. In this case, you can estimate your fertile days with the help of a personal fertility calendar and use this interval for unprotected sex. But for birth control, the calendar method is anything but suited!

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Daysy gives you 99,4% accuracy!

Daysy calculates your fertile days for you with an accuracy of 99,4%, giving it a very good Pearl Index of 0.6. The Pearl Index indicates how safe a method or means of contraception is. The lower the value, the safer it is in preventing a pregnancy. Daysy makes your natural family planning easy, comfortable and safe.

In order for Daysy to be able to calculate your fertile days as precisely as possible, you have to use it every morning before you get out of bed. All you need to do is take your basal temperature by placing the device's test prod underneath your tongue and waiting until you hear a signal sound. The measurement takes only 30-60 seconds! After that, Daysy might ask you to confirm via the push of a button that you are currently on your period, before displaying your current fertility status with a colourful light.

Red means that you are fertile and should either avoid to have sex, or alternatively use an additional barrier method like a condom or a diaphragm when having sex. If Daysy's light is green it means that you will not be fertile within the next 24 hours and don’t even have to think about birth control. Daysy always shows you precisely when you have to use contraception.


Calculate your fertile days: have an overview with Daysy's fertility calendar

But Daysy offers you even more: With the practical fertility app DaysyView for your smartphone, you can keep an eye on your current fertility calendar and access a convenient preview of the next month. The preview is also ideally suited to plan activities for when you do not want to be having your period, such as going swimming or doing certain types of exercise. DaysyView also displays your temperature curve. Beyond that you can take notes in Daysy's fertility app and record, for instance, the times you have had sex. If you want, you can also share this calendar with your partner. This way, he too will know in advance when to think about birth control.

With Daysy and its app DaysyView, nothing stands in between natural family planning and a self-determined love life!

290.00 EUR

incl. VAT and Shipping

Daysy is a fertility tracker that uses the fertility awareness method by learning and tracking your menstrual cycle.

Daysy is a fertility tracker that uses the fertility awareness method by learning and tracking your menstrual cycle.

  • Fertility tracker Daysy (incl. battery)
  • Connection cable for your smartphone
  • Instructions for use

Product available - Delivery time: 3-5 days*