Skip to content

Instantly share code, notes, and snippets.

Last active July 22, 2024 03:51
Show Gist options
  • Save xujiaao/63cb3bbea9fe22e79206e5eb7ba82d0e to your computer and use it in GitHub Desktop.
Save xujiaao/63cb3bbea9fe22e79206e5eb7ba82d0e to your computer and use it in GitHub Desktop.
Set the NTP server of your android device
Android Things

Set the NTP server of your android device

Just use this command to set a server address to automatically sync your device time. ( ͡° ͜ʖ ͡°)✧

$ adb shell settings put global ntp_server <new-ntp-server>


I have a Raspberry Pi 3 with Android Things installed on it. But the time is never synchronized...

After googling it, I found this piece of code in

public class NtpTrustedTime implements TrustedTime {
    public static synchronized NtpTrustedTime getInstance(Context context) {
        if (sSingleton == null) {
            final Resources res = context.getResources();
            final ContentResolver resolver = context.getContentResolver();
            final String defaultServer = res.getString(
            final long defaultTimeout = res.getInteger(
            final String secureServer = Settings.Global.getString(
                    resolver, Settings.Global.NTP_SERVER);
            final long timeout = Settings.Global.getLong(
                    resolver, Settings.Global.NTP_TIMEOUT, defaultTimeout);
            final String server = secureServer != null ? secureServer : defaultServer;
            sSingleton = new NtpTrustedTime(server, timeout);
            sContext = context;
        return sSingleton;

It shows that android tring to get NTP server from:

  1. Settings.Global.NTP_SERVER first

  2. Then

And the NTP server of my Android Things is, that's why it dose not work (I'm in China...).

Fortunately, it is easy to set settings via adb:

$ adb shell settings put global ntp_server

# test
$ adb shell settings get global ntp_server 



"I found "ntp_server_2" on settings." -- same for oneplus 7t pro (android 11).

In my case, even after changing both settings and rebooting, the system pid 1000 still attempts connecting to and i see no other process attempting to connect to the ntp server i set.

Anyone experiencing the same? Are there any other workarounds?

Copy link

smed79 commented Sep 24, 2022

$ adb shell settings put global ntp_server

Return the error message: Bad arguments

Fixed by:

$ adb shell settings put --user 0 global ntp_server

Thank you.

Copy link

I have 3 NTP addresses.

$ adb shell settings list global | grep ntp

If the first NTP server is unreachable, the device tries to connect to the first one, after which it connects to the next NTP server.
Now, the command adb shell settings get global ntp_server returns the first NTP server that is unreachable, it does not return the server to which it is connected.
Is there any adb command to know which NTP server it is connected to?


Copy link

Uj947nXmRqV2nRaWshKtHzTvckUUpD commented Nov 10, 2022

adb shell settings get global --- instructs on getting that specific config only and it is the expected behavior
to see how ntp actually connects using the current configurations, you would need to see the sync in action

There are actually more ntp servers used on android. System uses (defined normally by the global settings vars .. not 100% sure) while gps uses whatever is defined on gps.conf. For example i created magisk module to force gps to use or

Some things you can do:

  • for eg. you can use 3c network monitor, but since ntp sync does not happen so often you will not be able to see it in real time easily
  • you might need a script to watch for connections on port 123 and log them
  • or you can use some burp packet listener to monitor traffic from phone on pc
  • best bet is to use a vpn firewall like netguard which does the logging as long as traffic is routed through its local vpn. You will watch for system (pid 1000) or gps (pid 1021). in my attempts i could not force sync time, even rebooting or setting time to manual, as it remains cached somehow. but the sync normally happens at least once a day

running android 11. i think the behavior is different from phone to phone.

Copy link

Are you at liberty of sharing the magisk module that you created that forces GPS to utilize '' or ''?

Copy link

Uj947nXmRqV2nRaWshKtHzTvckUUpD commented Nov 10, 2022

I created a repo with it . The module itself is a port for compatibility with latest magisk (see references in readme). I used it in the last 4 months and observed an improved location locking than with the default gps.conf on my OnePlus 7T PRO. Let me know on how it works for you. Also I invite anyone to propose updated and improved optimizations in gps.conf

Copy link

You sir, are a gentleman and a scholar.

Copy link

ipcjs commented Dec 1, 2022 is a good choice in China.

Copy link

don-dolarson commented May 26, 2023

Thank you for this thread.

There is no existing ntp_server setting in LineageOS 20 but can easily be created just by pushing the "put global ntp_server domain" command through adb.

Setting is preserved between reboots and my router logs can confirm that NTP address changed from to the chosen NTP server. GPS automatically connects to (Cloudflare) in this ROM.

Copy link

wodeguaiguai commented Jul 21, 2023

Failed to execute this command, my devices is android 12 colorOS, it seems no write permisson

➜ /Users/guaio >adb shell settings put global ntp_server

Exception occurred while executing 'put':
java.lang.SecurityException: Permission denial: writing to settings requires:android.permission.WRITE_SECURE_SETTINGS
	at android.content.ContentProvider$
	at android.os.ShellCommand.exec(
	at android.os.Binder.shellCommand(
	at android.os.Binder.onTransact(
	at android.os.Binder.execTransactInternal(
	at android.os.Binder.execTransact(

Copy link

Thanks for the information. I've tried several servers, is the fastest one in China.

Copy link

In my device if I first of all do adb shell settings get global ntp_server, it returns null.

Copy link

costaht commented Jan 10, 2024

For those trying to connect to your TV, I used adb connect to connect to my tv via LAN. Once you run that command you're gonna have to click Accept on the pop-up that is shown on your tv screen.
adb devices should show your TV as active, then you can run the commands above.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment