Frequently Asked Questions

General questions about Daysy

Yes. If you sleep with your mouth open, just close it once and swallow before you measure. The measurement is finished when the temperature has reached its final value and you hear a soft beep beep from Daysy. Daysy may take a couple of seconds longer to measure for those users who sleep with their mouths open. Please be sure not to open your mouth while measuring.

No, in order to transfer your data from your Daysy 1.0 to your new Daysy 2.0 you will need to send your data file to customer support. Customer support will transfer your data file to your new Daysy 2.0 before it ships out. Please get in touch with customer support prior to purchasing a Daysy 2.0 if you’d like to have your data transferred.

To avoid damage, please do not place Daysy under your pillow. Keep Daysy in a safe place within easy reach.

No, Daysy is your individual fertility tracker with your individual data.

Daysy is programmed with a complex algorithm which evaluates your cycle by tracking your morning temperature (taken under the tongue) and knowing when you have your period. Daysy will then show you right away if you are currently fertile or not.

Yes, your initial Daysy order includes everything you need.

That depends on whether the medication influences your body temperature or your cycle. In general, you should skip measurements while you are taking such medication. If you have doubts, contact your doctor or our customer service team.

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.

Daysy 1.0: Remove the battery and store Daysy in a dry location in its original packaging, if available. You can find more information in the instruction manual.

Daysy 2.0: Please store it in a cool, dry location. While stored, please remember to charge your Daysy once every 2-3 months to maintain the internal battery.

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.

Based on its recorded data, Daysy can compensate for the occasional missed reading. We still recommend you measure as regularly as possible so that your fertile phase can be narrowed down as precisely as possible. If you have to skip measurements due to illness, Daysy will get back on track once you start again.

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.

Smoking should not influence the result. Alcohol, if consumed excessively or when your body is not used to it, does influence basal body temperature. If you can feel that you were drinking yesterday, you should skip your reading in the morning. If you feel just fine and have no headache or other symptoms of alcohol consumption, you are fine to temp as usual.

3-5 days. For more information please check our general terms and conditions.

Daysy comes with a 2-year warranty. You can find all the relevant information in the general terms and conditions.

Ideally, you measure daily. The fewer measurements you miss, the better.

A fever is when your body temperature reaches at least 38°C (100.4°F) degrees - if this is the case, you will most likely feel ill and you will notice that your temperature curve is unusually high (see example curve). The DaysyDay app will alert you that your temperature is high and recommend you temp with a standard medical thermometer. Temperatures above 37.8°C (100.4°F) or below 35°C (95°F) degrees are automatically excluded from the algorithm and will not be used for your fertility calculations.

Red = fertile / possibly fertile (On red days you can plan for a pregnancy.)

Red flashing = predicted day of ovulation

Green = infertile days (You are not fertile on green days.)

Yellow = learning phase/cycle fluctuation (Yellow days should be considered as red days.)

Red, green, yellow (blinking) = possible pregnancy

Tutorial for Daysy 1.0

Tutorial for Daysy 2.0

First things first: If you feel that there is something not right, you feel sick, or you have pain, never hesitate to consult your doctor! Most people tolerate vaccinations without any problems. Sometimes, however, vaccination reactions occur: These are almost always harmless after-effects of vaccinations, which in the vast majority of cases pass very quickly. Some vaccinated people react with a slight fever (below 39°C / 102°F), aching limbs or faintness. The fever can occur only a few hours after vaccination and last up to 3 days. Such vaccination reactions are usually completely harmless and no cause for concern. As a rule of thumb: If you wake up in the morning after the vaccination and feel different than usual, for example sick or overtired, then interrupt the measurements until you feel better again.

How do I use Daysy?

Use Daysy in the morning right 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. We do recommend that you sleep 3-4 hours before measuring.

Tutorial for Daysy 1.0

Tutorial for Daysy 2.0

Please contact your customer service for guidance.

One or two skipped measurements are not a problem; Daysy will simply use your earlier data to calculate your fertility. Multiple missing values per cycle will lead to a higher number of red or yellow days.

Simply press the activation button and your fertility status will be displayed.

No. Daysy will only record the first measurement of the day.

You can immediately start with the measurements. If you were using hormonal birth control before, stop using it before you begin measuring. The first bleeding after coming off hormonal birth control is a withdrawal bleeding and must not be entered as your period. If you are menstruating when starting with Daysy and you cannot enter all days, do not enter the current menstruation, but the next one. The first day of menstruation is important because it marks the beginning of your cycle.

Below the tongue in the pocket next to your frenulum and with your mouth closed. It is best to measure on the same side each morning if comfortable.

Yes, you can. Daysy is also reliable during the transition to menopause. If your ovulation is delayed or doesn't occur, Daysy will display more red and yellow days. Using Daysy will allow you to directly observe the changes that are happening to your cycle.

Yes, Daysy can be used while breastfeeding. You should not start measuring until 6 weeks after birth. Since there is no way to predict the first ovulation after birth, Daysy will stay yellow until the first menstruation is entered postpartum. Once you enter your first period, Daysy will display fewer red and yellow days in the following 2-4 cycles as Daysy gets to know your unique cycle rhythm.

Daysy 1.0: If you traveled overnight, skip the first measurement after your arrival and continue to measure regularly the next day after resuming a normal sleep cycle. Do the same thing when you return home from traveling.

Daysy 2.0: When traveling with your Daysy, it is important to set the time on your Daysy to the local time before resuming your temperature readings. Set your mobile phone to the local time zone (many phones will do this automatically) and synchronize your Daysy with DaysyView/DaysyDay to set the time on Daysy. Take your temperature and resume use as normal the next morning.

Yes, you can always rely on Daysy. If you have to skip a measurement after a sleepless night, Daysy will still reliably display your fertility status. Depending on where you are in your cycle, Daysy will react accordingly.

It will take approximately 60 seconds to measure.

Daysy automatically switches off after 60 seconds.

No. Daysy only records the first daily measurement. If you have concerns about a reading, please contact our customer service team.

No. What is important is that you measure immediately upon waking after getting 3-4 consecutive hours of sleep, before getting up and being active.

When Daysy displays a red light, it means that you are fertile. You can check your status anytime by activating Daysy.

Yes. Daysy has been designed for women like you. Simply take your temperature when you wake up.

Daysy 1.0: Daysy only registers one measurement after 18 hours have passed since your last reading.

Daysy 2.0: Daysy only registers one measurement per day. If the next day has not yet started, a tone (beep-beep) will sound.

Yes, but for the optimal use of Daysy we recommend that you sleep at least 3 consecutive hours before measuring.. If you don't get that during certain nights, there is no reason for concern. Daysy can handle skipped measurements from time to time.

Yes, please take your temperature throughout your entire menstrual cycle. However, on some days you should refrain from taking a measurement: for example, after excessive alcohol consumption, when you are ill (fever) or when you are feeling very bad.

Turn on Daysy. Press 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 flow for a minimum of three consecutive days. You can change 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.

Tutorial for Daysy 1.0

Tutorial for Daysy 2.0

Questions about "DaysyDay"

The intended use statement for your app can be found in the Main Menu of the app under Info - DaysyDay Information.

The serial number of your app (sometimes referred to as the version number) can be found in Settings > Info > DaysyDay Information. This number may be asked for by customer support when assisting with app related concerns.

Android phones require the app to have access to the phone's location data in order to enable Bluetooth® communication. Please rest assured that this is strictly an Android requirement. The DaysyDay app and Valley Electronics are not collecting, storing, or accessing any location information. This is strictly to allow the app to communicate with your Daysy via Bluetooth®.

No.DaysyDay will only import data from Daysy or the additional tracking information you have manually entered.

These horizontal lines run through your average low and high temperatures of each cycle, calculated once the cycle has closed. Because basal body temperature values naturally fluctuate each day, these lines can help you visualize the temperature step that occurs after ovulation. To learn more about how Daysy identifies and uses this temperature step to calculate your daily fertility, please read the article The Fertility Tracker Method.

When you synchronize Daysy with DaysyDay, all data on Daysy is transmitted. You can also manually add period flow, cervical mucus, intercourse, and other personal tracking information.

Open the app and click on the "Connect your Daysy" button.  Select the appropriate button for the model Daysy you have, Bluetooth® or Cable, and then follow the on-screen instructions to connect your Daysy. For Daysy 1.0 (Cable), connect the cable to Daysy and then to your phone and then turn Daysy on. Occasionally, disconnecting and reconnecting the cable may be necessary if the phone does not recognize that Daysy is connected.  For Daysy 2.0, press the button on Daysy once to turn it on and then double press the button to activate Bluetooth mode. Make sure Bluetooth® is activated on your phone and the app has permission to access the Bluetooth®. You will see a synchronization animation and then you will be prompted to enter your email address and the pin code you receive via email. Once completed, you will see your data displayed on the calendar and temperature curve.

Tutorial for DaysyDay

"DaysyDay" is an app available for free download in your app store. When used and synchronized with Daysy, the app displays your past, current, and future fertility statuses and provides additional insights to help you learn more about your cycle.

DaysyDay Partner requires internet access so that the app can display the most current data retrieved from the server after the Daysy user's most recent synchronization. This is also required in case permission levels have changed and access to certain data has been granted or removed.

Questions about my cycle

Daysy expects a certain amount of normal irregularity. For optimal use of Daysy, cycle lengths of 19-40 days are the ideal requirement. The statistics in the app display the ovulation range. If your ovulation fluctuates by more than 4 days or if your cycle length lies outside the 19 - 40 day range, please contact our team of experts.

It is normal for cycles to fluctuate. If you're unsure, feel free to contact our customer service.

Certain "strict" diets can lead to cycle irregularities, often times causing your period to come later. If you're unsure, reach out to our support team.

Yes. Irregular cycles are generally not a problem for Daysy. Even with irregular cycles, Daysy distinguishes between infertile and possibly fertile days with a very high accuracy. However, in case of extreme fluctuations, using the device is not very beneficial, because you would get proportionally more “yellow days” displayed. 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.

No, over-the-counter pain medication will not influence the measurements. The common additional antifebrile effect does not influence the basal temperature. However, please do not temp if you're using these medications to control a fever. If you're unsure, please contact our customer service.

Only very few (hormone-free) medications have a direct influence on your measurements, but often the reason why you are taking medication can influence your temperature (e.g. fever or stress). Hormonal medication will influence your temperature and should under no circumstances be taken in combination with Daysy. If you're unsure, consult with your doctor or contact our customer service.

The typical influences on your temperature and cycle include:

● excessive amounts of alcohol ● sleep deprivation ● disease or illness ● chronic physical or emotional stress ● significant exercise ● strict dietary restrictions / starvation ● malnutrition ● travel

Once you know the cause, many irregularities in your cycle are easy to reverse. Feel free to reach out to our customer service to discuss your temperature curve.

If your efforts to become pregnant have not been successful within six to twelve months, consult your physician.

Technical Questions & Troubleshooting

Daysy 2.0: The blue light on your Daysy's activation ring will move from the bottom upward while charging. All of the blue lights will light up once the battery is fully charged. Daysy may enter standby mode while charging. Simply press the button to check the charging status.

Daysy 2.0: Before you contact our support team please try to charge Daysy with the USB cable at the USB port of your PC or phone charger over night. While Daysy is connected to the power supply, push the button once. Check if the charging indicators show up (rising if charging, full ring if charging complete). If yes, wait till the charging is completed and remove the USB cable. If Daysy still does not wake up again, please contact our support team for further instructions.

Daysy 1.0: If your Daysy makes the “grumble-buzz” sound when you are trying to enter the temperature reading mode, this is Daysy’s way of indicating that the cable is still connected or she thinks the cable is connected. If your cable is connected, please turn Daysy on, remove the cable and then press the button again to enter the temperature reading mode. If your cable is not connected, then please turn Daysy on, insert and remove the cable several times, then press the button again to enter the temperature reading mode. If Daysy makes the “grumble-buzz” sound when you are recording your temperature, then she is indicating that your temperature value is too low, too high, or too unstable. Please make sure you have removed the cap from Daysy sensor before placing it under your tongue, that your lips are closed around the neck of the sensor, and you do not move the sensor around while recording.

Daysy 2.0: The "beep-beep" sound is Daysy's way of indicating that temperature reading has already been recorded for this day. Please wait and take your temperature tomorrow morning. A temperature reading can only be recorded once a day.

Daysy 2.0: Please contact your local customer support team.

Daysy 1.0: The battery life of the battery we supply with your order is about 2 years. Daysy's activation ring will signal a weak battery with rapid blinking. Please exchange the battery within 2 days as instructed in the manual.

Daysy 2.0: A single battery charge will last 1 to 2 months, depending on how often you use your Daysy. To indicate that the battery is nearly empty, the activation ring on your Daysy will flash at frequent intervals. Make sure you charge the battery within a week.

If Daysy finishes a measurement by vibrating, repeat the measurement. Make sure to hold Daysy still and your mouth closed while you take your temperature. Please note the cable cannot be inserted into Daysy while recording a reading.

No. Daysy records all your data and keeps it safe. If you have synchronized Daysy with DaysyView/DaysyDay, you can also store your data online to keep it safe in case Daysy gets lost or stolen. If that happens, please contact customer service.

No, since you measure below the tongue, these factors have no influence on the measurement.

Daysy 1.0: Yes, use an adapter that fits your smartphone, but stick with Daysy's connecting cable.

Daysy 2.0: Yes, Daysy now syncs to your smartphone or tablet via Bluetooth®, so you don't need an audio outlet to sync with DaysyView/DaysyDay.

Daysy 1.0: Daysy uses a CR2032 battery which can be purchased anywhere standard batteries are sold.

Daysy 2.0: Daysy now has an internal battery that charges by connection to a power source using a microUSB cable which is included with your Daysy.

Use a damp cloth to carefully clean the sensor on your Daysy. You can also use a little alcohol or soap if you wish. Since your Daysy is not waterproof, make sure that only the neck on the sensor and not the whole appliance comes into contact with water.

We recommend the following steps for cleaning your Daysy:

  1. Clean the sensor neck and tip with lukewarm water and/or mild soap before and after each use.
  2. Dry with a clean cloth.
  3. Replace the protective cap after drying.

These steps will reduce the number of germs or possible viruses on the surface of the device. This cleaning is sufficient for daily personal use with Daysy.

If the device needs to be disinfected as well, the following steps can be practiced:

  1. Wash your hands thoroughly or wear disposable gloves.
  2. Clean the sensor neck and tips (as per steps 1 & 2 listed above).
  3. Moisten the sensor neck and tip with a disinfectant (limited virucidal), alcohol (60-80%) or isopropanol 70%.
  4. When necessary, a cotton swab can be moistened with disinfectant and inserted into the protective cap to clean the inside.
  5. Allow to air-dry (the sensor neck should not touch any other objects or surfaces).
  6. Place the protective cap back on your Daysy.

Information COVID-19:

We are taking precautions as necessary, with staff wearing gloves, use of Personal Protective Equipment and increased cleaning methods. All products are disinfected prior to shipping.

Coronaviruses are encased viruses, meaning they are encased in a lipid envelope. All disinfectants with a virucidal (antiviral) or limited virucidal spectrum of efficacy are effective against coronaviruses. A list of all tested and approved disinfectants to fight Covid-19 is available from United States Environmental Protection Agency found here:

The agents listed can inactivate the corona virus, which means it loses its ability to be infectious. This can be done in different ways:

· Denaturation -> destruction of the virus surface · Removal of lipids from the virus envelope -> e.g. alcohol · Impairment to the nucleic acid of the viral genome

Alcohol is capable of destroying the virus shell and can often be found already in your home. Alcohol that is 60% alcohol is effective in inactivating the virus. However, 100% alcohol is not effective because only alcohol with a proportion of water allows the lipids to be dissolved from the virus envelope. An alcohol volume between 60% and 80% is therefore recommended. Isopropanol (70% )is also a suitable agent for the inactivation of COVID-19. You can learn more about cleaning and disinfection for households from the Centers for Disease Control and Prevention here:

If for some reason, the increase in temperature is very low, Daysy will switch to displaying red days for a longer period, before switching to yellow days and, eventually, back to green days. A low rise in temperature can be an indication of a hormonal condition. During anovulatory cycles, no rise in temperature is registered because ovulation did not occur. Corpus luteum insufficiency (CLI) is another possible reason for a low or indeterminable rise in temperature because the body doesn't produce sufficient progesterone to make the basal body temperature (BBT) rise. Menopausal women can also register lower increases in temperature, because their estradiol and progesterone values are declining.

Not really. On average, a woman's temperature increases by 0.3 degrees Celsius. If yours rises by more than 0.5 degrees Celsius on average, please contact our customer service.

Daysy 1.0: The battery should not be removed for any reason. If Daysy's battery loses contact, it will stay yellow until the next menstruation is entered. The data you have already saved within Daysy is still there.

Daysy 2.0: Daysy does not have an accessible battery compartment. Please do not attempt to open your device or remove the battery as this will automatically void the warranty.

Please contact your local customer service.

Daysy 1.0: Please use a coin and turn the cap counter-clockwise to open the battery compartment.

Daysy 1.0: Make sure that you are following the correct order of steps to facilitate synchronization. Please contact your local customer service team if you have further trouble.

Daysy 2.0: Please make sure that Bluetooth® is enabled on your device and on your Daysy. To enable Bluetooth® on your Daysy, wake Daysy up and press the activation button twice (blue light blinking). Now select the Sync button in the top right corner of the app to start the synchronization process. Daysy is communicating with the app when the blue light remains illuminated. If the blue light on Daysy keeps blinking, please check the Bluetooth® mode on your phone again. If you have further trouble, please contact your customer support team.

Please contact your local customer service to discuss next steps.

If no replacement parts are shown in your shop, please contact your local distributor.

Tutorial for Daysy 1.0

Tutorial for Daysy 2.0

DaysyView: After resetting your Daysy, please open DaysyView and select the serial number from the main menu. Select OK to confirm the selection to "Forget this device." This will erase all data from your app so that only the new data is seen when you sync again.

DaysyDay: After resetting your Daysy, please open DaysyDaysyDay and open the "Settings" menu. Select "Unpair Daysy" under "Profile" on the "Account" page.Click the "Unpair Daysy" button and then "Unpair" in the popup window to complete the process. This will erase all data from your app so that only the new data is seen when you sync again.

Please open your DaysyView app to the Main Menu page and then choose Settings. Now scroll to the bottom of the page and click on the Check for Update button. You will then see a series of on-screen instructions to guide you through the update process.

Questions about the "Daysy" update

Please make sure you are not activating the Bluetooth mode on your Daysy until after you press Start on the app. Waiting until you get to the instruction screen that tells you to activate Bluetooth mode on Daysy should enable a good connection.

The update to your Daysy was not successful. Press the button on Daysy one time to remove the incomplete update. Your Daysy will still function as normal. When you are ready, you can try the update again by choosing "Check for updates" from the settings menu.

Your Daysy has been successfully updated. You can confirm this by choosing "Check for updates" from the settings menu.

While the update is not mandatory, it is very highly encouraged. Phone and app technologies are continuously improving and this update has been made available to help keep up with these changes. If you choose not to update, you may find that you have more difficulty synchronizing with the App, but your Daysy will continue to measure your temperature and calculate your menstrual cycle status without any trouble.

Updates to your Daysy are rare. However, as technologies continue to improve, if there are updates that can be made to the existing hardware to improve usability of your device, we will make these available.

Currently, the update is only available through the app.

Please make sure your phone is not connected to other Bluetooth devices when trying to update and you have a good internet connection to download the update file. If failures continue to occur, please contact your local support team for specific assistance.

The update is only available for Daysys with certain Bluetooth modules. If you are having trouble synchronizing, please contact your local support team.

The current update is to improve the Bluetooth communication pathway on your Daysy, which then improves synchronization with the DaysyView app. This update is provided to keep up with improving and emerging technologies in apps and phones.

No. The current update is to improve the Bluetooth communication pathway on your Daysy, which is separate from where your data is stored on the device. However, a current synchronization is required before performing the update so there is also a backup of your complete data file on our secure server as an extra safety precaution.