11/28/2025 8:56 a.m.

First steps with Daysy

Hi! Welcome to the Daysy family! Your start into a world full of cycle knowledge

We’re glad you’re here. Tracking your fertility with Daysy is going to be easy, but like with every new beginning, there’s a few things to know before you get started. Please remember it’s natural to feel a little unsure of things at first, but soon you and Daysy will come to know each other closely, and you’ll love the newfound knowledge of your cycle and fertility!

Before you begin:

Before you start using Daysy, there are a few important points to keep in mind so you can take accurate and reliable measurements from day one. Whether you’ve recently stopped hormonal contraception, want to know the best time for your first measurement, or need guidance on tracking your period, these simple tips will help Daysy evaluate your cycle optimally. Take a moment to read the advice below, then begin your Daysy routine feeling calm, confident, and well prepared.

Your first steps with Daysy

  • If you’re on hormonal birth control, you must stop before using Daysy. You can start temping the day after you’ve quit. Remember – the first bleeding after stopping HBC is a hormonal withdrawal bleeding, not a true period, so please do not enter it into your Daysy as a menstruation.

  • Plug your Daysy in to charge, doing it overnight before temping the next morning is great, so you’ll be all ready to unplug and temp tomorrow when you wake. The charge should then last 1-2 months!

  • If you’re currently menstruating, and it’s not the first day of your period, please do not enter menstruation for this cycle. Menstruation always needs to be entered starting on the first day of active bleeding and flow. You don’t want Daysy thinking the third or fourth day of your period is actually the first.

  • If you’re sick with a fever, hungover, or didn’t sleep well last night, please do not temp, and take good care of yourself! You can temp again when these issues have passed.

  • It’s exciting to get Daysy and you want to start now, but first sleep! You can temp with Daysy tomorrow. Be sure to use Daysy daily right after you wake up, before you get up and get active. For optimal use of Daysy, we recommend that you have at least 1 hour of continuous sleep before measurement.

You can find more information here:

How to measure correctly with your Daysy

For reliable results, it’s important to measure your basal temperature the same way every morning. With just a few simple steps, you can ensure that Daysy records your data accurately and evaluates your cycle as precisely as possible.

How to measure in 3 steps:

  • While lying down, immediately upon waking, take the cap off Daysy, and press the button once to turn Daysy on. Press the button once more to see the blue rotating lights (temperature taking mode). Place the sensor in one of the side pockets under your tongue, with your mouth closed. No need to over-insert or push too hard. Keep it comfy!

  • Daysy will swirl the blue lights while taking your temperature (usually takes around 1 minute) and wait to hear the little "beep beep" from Daysy telling you that your reading was captured.

  • Check out your fertility indicator light from Daysy, which pops up on your device as soon as your reading is finished! If you aren’t sure if a successful temp was captured, you can double check by trying to go back into temperature reading mode. If it doesn’t let you go into temp mode again, then a successful temp was already captured for the day!

This is how you enter your menstruation correctly

To ensure Daysy can evaluate your cycle accurately, correctly entering your menstruation is especially important. With just a few simple steps, you can make sure your data is complete and recorded correctly. Here’s how to enter it:

How to enter menstruation on Daysy in 3 steps:

  • After you’ve taken your reading for the day, hold down the button until you hear a beep and see the green petal and solid violet lights come on in the activation ring.

  • Enter menstruation for at least 3 consecutive days when you’re having active bleeding and flow. No need to enter menstruation when having light spotting/staining.

  • If you need to edit menstruation within the 3-day editable window, please check out the FAQ below or the tutorial!

DaysyDay is the Daysy app!

With Daysy and the DaysyDay app, you have all the knowledge and tools you need to identify your fertile and non-fertile days. This empowers you to make informed and confident decisions about your menstrual cycle, your fertility, and your overall health.

How to synchronize in 3 steps:

  • Open the app and press the activation button to turn on your Daysy.

  • Press Daysy’s button twice to activate Bluetooth®.

  • Synchronization begins and imports any new data since your last sync!

What to do and what not to do

To get the most out of Daysy, it’s important to know which habits are helpful and which to avoid. This overview clearly shows you what to do and what’s better to skip.

Do:

  • Temp regularly and immediately after waking up.

  • Remove cap before temping.

  • Enter menstruation only on days of active, bright red flow, making sure cycle day 1 is always correct.

  • Enter at least three consecutive days of menstruation.

  • Charge Daysy every 1-2 months for uninterrupted use.

  • Clean Daysy before and after every use.

  • Store Daysy in a hard case (hard sunglass cases work great!) to protect her from children and pets.

  • Contact us via email or phone if you have any questions or concerns!

Don´t do:

  • Do not temp when you have a fever, have an infection, or are unwell.

  • Do not temp the morning after drinking alcohol.

  • Do not use Daysy while on hormonal birth control.

  • Do not enter menstruation on days that you have spotting or light staining.

  • Do not use Daysy if your cycles consistently go beyond 40 days.

  • Do not stress! You’ve got this!

Daysy vs DaysyDay-Anzeige:

  • Daysy stores your data, does all of your fertility calculations, gives your fertility indicators, and allows you to edit menstruation for up to 3 days.

  • Since Daysy stores all of your data, you don’t have to sync every day, only when you feel like seeing your cycle information within the app.

  • DaysyDay shows you your calendar view, cycle statistics, temperature curve, and allows you to make notes about cervical mucus, sexual intercourse, and more.

  • Syncing with DaysyDay requires you initiating Bluetooth®. It’s not always searching, so it’s not always emitting radiation to protect you while you’re sleeping.

  • Syncing with DaysyDay means your data is backed up on our private and secure server. Your data is safe and never sold. You can read everything in our privacy policy.

Our most common FAQs:

What is the best way to measure?

For optimal use of Daysy, we recommend that you should have slept sufficiently (at least one hour) before the measurement. It is important that you take your temperature immediately after waking up, before getting up and becoming active. Measure below your tongue, with your mouth closed, and keep the device steady while it is measuring. Video Tutorial

Do I have to measure at the same time every day?

No. You should have at least one hour of good quality sleep before the measurement. It is important that you take your temperature immediately after waking up, before getting up and becoming active. For optimal use of Daysy, try to get at least 3 or more hours of sleep before measuring. Less sleep can result in more temperature fluctuations causing Daysy to give more fertile or potentially fertile days.

How do I enter or edit menstruation?

You can confirm or remove menstruation at any time during the current day. Simply press the button to turn on your Daysy, and then press and hold the activation button until the violet light lights up without flashing and you hear a "beep." Confirm you are menstruating for each day of active bleeding and for a minimum of three consecutive days. You can also remove menstruation data for the same day by turning Daysy on and pressing and holding the activation button until the purple/blue light is no longer solidly lit and begins flashing again.

Video Tutorial

How long until Daysy knows my personal cycle?

The first 2-4 cycles of use are considered Daysy's learning phase. Over the course of her learning phase, Daysy will come to understand your cycle and begin narrowing down your fertile window. Daysy remains quite cautious and conservative during this time, which is why Daysy is accurate starting the very first day.

When can I start to rely on Daysy's results?

You can rely on Daysy's results starting the very first day of use. In the beginning, you will see more yellow and red days because Daysy is still learning your unique cycle. You will see more green days as Daysy comes to understand your cycle and can narrow down your fertile window. The more regularly you measure, the better.

My cycle is irregular. Can I still use the devices?

Yes. Irregular cycles are not a problem for Daysy/Lady-Comp. Even with irregular cycles, all Valley devices distinguish between non-fertile and fertile days with a very high accuracy. However, in case of extreme fluctuations between cycles it will give you more red and yellow lights and less green lights. Fluctuations of several days are usually not a problem. If you have questions about your unique cycle, please reach out to our team of experts.

Are there any costs associated with the DaysyDay app?

No! DaysyDay is free! There are no in-app purchases or upgrade fees.

Does illness reduce the reliability of the device?

In general, you should skip measurements during illness and while you are taking medication that can have an influence on your body temperature or cycle. If you have doubts, contact your doctor or our customer service team.

More: Contact

Discover More About the Daysy Cycle Tracker

If you want to dive deeper into the world of Daysy, our website offers plenty of additional information. From tutorials and FAQs to insightful articles and helpful app resources. And if you have questions or need support, our team is always here to help.

Daysy Tutorials

Step-by-step guides & helpful tips for using Daysy.

Daysy FAQ

Everything you need to know about Daysy, all in one place.

DaysyDay App Information

Track your cycle & fertility smartly.

Get more information in our blog

Your Guide to Reading Basal Temperature Charts. Learn how to recognize typical temperature patterns and interpret signs of potential health changes.

By understanding your cycle, you can adjust nutrition, mood management, and exercise to align with hormonal changes, using your cycle consciously to your advantage.

Learn when cycle irregularities are harmless and when it’s wise to see a doctor. Discover important warning signs, like missed periods or very heavy bleeding.