Owners of Xiaomi’s smart temperature and humidity sensors often face the unfortunate situation of displaying incorrect time on the screen, which can be a few hours behind, or even the date corresponding to the moment the device was initially turned on at the factory.
A key feature of most hygrometer models, such as the Qingping Air Monitor or Bluetooth Thermometer, is the lack of a built-in Wi-Fi module for direct synchronization with Internet Time Servers (NTP), which relies on a connection to a smartphone via a gateway or direct connection to get up-to-date data, and this is where the most common cause of the failure lies.
In this guide, we will discuss in detail the algorithm of actions that will allow you to force synchronize your device clock. We will look at the settings inside the Mi Home application, the features of working with regions and the specific actions for different sensor models to make your smart home work flawlessly.
Reasons for time desynchronization on sensors
Understanding the cause of the problem is half the success of solving it, and the main reason why time on the hygrometer is lost is because of the Bluetooth Low Energy (BLE) architecture that many of Xiaomi's compact sensors run on, which consume minimal amounts of power, so they don't have a constant link to the router or the cloud.
The second important factor is changing time zones or switching to summer/winter time in the smartphone operating system. If your phone has automatically switched to new time and the Mi Home application has not sent an updated data packet to the sensor, desynchronization is inevitable. Also, it is worth considering that some models have a built-in battery-pill to store time settings, and when it is discharged, the clock can be reset to factory values every time the main battery is removed.
⚠️ Note: If you have changed region in the Mi Home app (e.g. from Russia to China), time on devices may reset, as servers in different regions may have different timestamps for old data.
Finally, a third cause may be a software bug of the application itself: Mi Home interface updates sometimes cause the background synchronization function to stop working properly, requiring manual user intervention to restart the synchronization service.
Preparation for setting up and checking the connection
Before you start complex manipulations, you need to make sure that the basic conditions for communication are met. Make sure that your smartphone is in close proximity to the hygrometer. For Bluetooth devices, the distance should not exceed 5-10 meters without obstacles, although it is better to come close to the synchronization packet for guaranteed transmission.
Check the status of the connection in the application. Open Mi Home, find your sensor in the list of devices. If there is a gray icon or an offline status near the device icon, time synchronization is impossible, in which case you first need to restore the connection by replacing the battery or rebooting the gateway if the sensor is connected through it.
☑️ Checking before synchronization
It is also important to check whether geolocation is enabled on your smartphone. In modern versions of Android and iOS, Bluetooth scanning and transferring system data (including time) often require permissions to access the location. Without this, the communication protocol can work unstable.
Synchronization through the Mi Home app
The most common way to set the time on Xiaomi hygrometer is to use the standard functionality of the application. The process may vary depending on the type of connection of the device (direct Bluetooth or through the gateway).
For devices with direct Bluetooth connectivity (e.g. Xiaomi Mijia Bluetooth Thermometer 2):
- 📱 Open the Mi Home app and make sure Bluetooth on your phone is turned on.
- 🔗 Click on the device icon to enter the control interface.
- ⚙️ Click on the three dots in the upper right corner to enter the settings.
- 🔄 Find the option “Sync Time” or simply hold your finger on the utama screen (the main screen of the device) until you see a message about successful sync.
For devices connected via a gateway, the procedure often happens automatically when the gateway has internet. However, if time is lost, try changing the time zone setting in the application itself. Go to Profile → Settings → Region and switch to the neighboring one, and then return it, which will force the devices to reconnect to the server and update the time stamps.
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If automatic synchronization does not occur, try temporarily turning off Wi-Fi on your smartphone and leave only Bluetooth, then reopen the device card.
In some cases, removing the device from the app and re-additioning it helps. When you first install it, Mi Home always asks permission to use the phone's current time, and that request is sent to the gadget at the time of pairing.
Setting time on different models of hygrometers
Xiaomi and partners’ eco-gadgets (Qingping, Lywsd03MMC) are diverse and have different implementations of time management. Below is a table that helps define the synchronization method for popular models.
| Model of the device | Type of connection | Method of setting the time | Screen availability |
|---|---|---|---|
| Mijia Bluetooth Thermometer 2 | Bluetooth | Autosynchronization when opening the card | Yes (E-ink) |
| Qingping Air Monitor Lite | Wi-Fi / Bluetooth | Through Wi-Fi settings in the app | Yes (LCD) |
| LYWSD03MMC (Round) | Bluetooth | Only through the Mi Home app | Yes (E-ink) |
| Mijia Smart Humidifier | Wi-Fi | Synchronization through the cloud Xiaomi | No (indication in annex) |
The Qingping Air Monitor is a more complex device that has its own operating system, and if time is lost, check the settings in the device's menu by clicking on the touch screen, and there may be a Settings → Date & Time item where you can turn off automatic sync and set the time manually, although this is not recommended because of the possible drift of the clock.
For simple LYWSD sensors without a display (which only transmit data to an application), the concept of “time on the device” is often conditional. They transmit data with a time stamp for the transmission moment. If the time is displayed in the application is incorrect, the problem lies not in the sensor, but in the application cache or server.
Use of alternative software for synchronization
If the Mi Home app doesn't work, third-party utilities can come to the rescue. For advanced Android users, there are apps that allow you to interact with the user. BLE-Directly using devices, bypassing cloud services.
One popular solution is the Notify for Mi Band app or specialized sensor utilities such as BlueMaestro or nRF Connect. However, for mass time synchronization, the ATC MiThermometer app (for Telink chip devices) has proven to be the best, allowing you to reflash the sensor and adjust more flexible data transfer, including synchronization frequency.
To use these methods, you will need:
- 📲 Android-based smartphone (on iOS, options are limited).
- 🔧 Installed third-party application (e.g. Flasher for ATC).
- 🔋 Full battery charge in the sensor (the process may take time).
- 💻 Risk readiness (flashing can void the warranty).
⚠️ Note: Using third-party software and flashing devices may result in loss of warranty and inability to connect the device to official Xiaomi servers in the future.
Often, after flashing on an alternative (firmware) from the ATC community, the device begins to broadcast the time received from the phone, much more stable, as the advertising intervals become shorter and more customizable.
Problems with time zones and region
A common mistake is to choose the wrong region when you first set up your Mi Home account, and if you are physically located in Europe, the server may send the wrong time stamp, especially during the daylight saving time, which is not used in China.
The solution is to check your account settings. Go to Profile → Settings → About the app and make sure the app version matches your region. Sometimes cleaning the app cache helps. Go to Phone Settings on Android → Apps → Mi Home → Memory → Clear cache. Don't confuse it with Clear Data, as this will require re-authorization and configuration of all devices.
What if time goes out after every power outage?
Also, check the time settings on the smartphone itself, make sure that the option "Use network time" or "Automatic time setting" is enabled. If the phone is manually set and erroneous, the hygrometer will synchronize and accept this incorrect data.
FAQ: Frequently Asked Questions
Why does the hygrometer show the time of 00:00 or 1970?
Can I set my time on a hygrometer without a phone?
Does changing the battery affect the timing?
How often do I need to manually synchronize time?
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Stable operation of time on the hygrometer depends on three factors: a good battery, the right region in the Mi Home application and Bluetooth/Geolocation permissions on the smartphone.
In conclusion, setting the time on Xiaomi hygrometers is a process that is usually solved by simply updating the communication in the application. However, if the problem is systematic, you should pay attention to the compatibility of software versions and the state of the hardware of the device.